I agree. I do not want our actions to indicate aggression in any way, but yes, let us approach and make them aware of our presence.

The xorn is the first to emerge from the tunnel; the four svirfneblin stand behind the strange elemental creature. A male gnome, entirely bald, has his shortbow at the ready. Two other males, identical twins, are equally ready for any sort of trouble. One wields a light crossbow, the other a war pick. The only female holds a wand in her right hand while keeping her left on the xorn's torso. 

The openness of your greeting and the explanation you provide for your presence removes some, but not all, of the tension. The female takes hold of the letter delivered to her by Donir's homunculus. After scanning it quickly, she introduces herself and the others in perfect Common. "I am Nim, and this,"--pointing to the baldheaded gnome--"is Rizzlepick. The brothers are Glint and Gleer, and this fellow here,"--patting the stony elemental on one of its three legs--"is Crunch."

The xorn then emits a bizarre series of syllables from its cavernous mouth. Nim responds to the xorn in the same language (Terran, you surmise) and then offers a translation for you. "Crunch greets you and...wants you to know your gemstones smell delicious." 

You are immediately reminded of the two pieces of jade, the spinel, and the amethyst you picked up from the annis hag's horde.  Apparently, the stories of a xorn's acumen for locating precious stones are true. 

"This letter from our friends in Rauvincross is a strange thing," remarks Nim. "Stranger yet is that anyone would seek the Hi-Thoror orcs."

At the mention of the Hi-Thoror, the three male gnomes quickly cast puzzled glances at one another. 

Patrin offers the gnomes, and xorn, a bow in greeting. ‘Nim, Rizzlepick, Glint, Gleer and Crunch, I greet you. I am Patrin Akambherylliax. We’ve been asked to help reduce the threat these orcs pose to the region. In particular by dealing with their leader, Kridash, who is believed to pose a very particular threat...’

Fargoth leans in close to Patrin and whispers to him.  "Perhaps the gems we found earlier could be offered as a gift?

Brevig overhears Fargoth, and nodding approvingly to the elf, kneels before the gnomes, bows his head with deference, and his baritone voice rings out, "You see before you Brevig, of the Holy Order of the Knights of Samular, of Waterdeep. We beg your good will and to be brought to the one of your kind named Torin, who knows well the Eldars of Rauvencross and may speak on our behalf. We also bring a small token of appreciation for your kind greetings and hospitality.” Brevig presents (or asks whomever is holding them to present) the gems in the manner of an offering.

At the mention of delicious gems, Donir's homunculus shies back, coiling around his arm. He absently strokes its metal head as he speaks.

"I am Donir Evenfeet, artificer, devotee, and warrior for Tyr the Evenhanded. I am glad to meet you, friends."

"Fargoth Applethorn..."  The elf nods to the gnomes, but doesn't feel the need, as a Harper, to give them his lineage, recent history or any sort of job title.

Speaking in Undercommon with hushed voices, the four grey gnomes exchange several sentences with one another. When they conclude their conversation, Rizzlepick turns to the party and, in halting Common, says, "To face Kridash is great matter. The orc chief takes lives and gives sorrow.  He takes Torim's life. He takes all other lives but not our lives. The rocks we stand upon are his enemy."

Nim then steps forward and softly says, "We are thankful" as she accepts the offering of the four gemstones.  "We four are all who remain of the enclave of Torim Wickelstone. It has been so for many weeks now."

She then provides a bit of recent history of the svirfneblin enclave and its interactions with the Hi-Thoror:

After her explanation, Nim and the other gnomes exchange a few more words in Undercommon with each other. One of the twins, Glint, then speaks to the group, his Common also a bit rough. "Two paths to Delvindraz. One path through tunnels and caverns: what you call back door. Another way uses steep path outside: what you call front door. Both paths dangerous."

Gwin has remained mostly silent except to offer her name in brief introduction, however, when the gnomes have finished their narrative the cleric bows in gratitude. We thank you for the history, information, and guidance. If I may ask another question. Glint, you speak of two paths, both dangerous. Are you able to identify the specific dangers of each path?

Patrin’s eyes soften in sympathy. ‘I’m so sorry for your loss. It’s a small consolation, but we will endeavour to avenge your friends and family..’

Nim locks eyes with Patrin. "Kind words and a brave heart."

Glint, in response to Gwin's query, says, "Back door is dangerous. Many tunnels allow orcs to attack from behind. Front door is dangerous. Must climb many stairs, and orc spears fall like rain."

"If they know we are coming," adds Nim. 

Brevig listens to the tale with growing alarm, his countenance ashen with sorrow. Standing now, but unable at first to meet the gnomes' eyes, he responds, "Your tale pierces my heart, and your sadness -- to lose so many when your numbers are already few -- cannot be guessed at." Then, directly to Rizzlepick, he says, "If there is anything I can do to give relief to your suffering...the Morning Lord gives solace even in dark places, and I am his willing exponent."

On the heels of Patrin's words, Brevig nods sympathetically, letting his compatriot's condolences speak for the group.

When the exchange moves more fully into how to approach Delvindraz, Brevig voices a request. "We would be grateful if you would take us as far as the point where the two paths diverge. There, we can decide which one to follow. I would like to see the two ways with my own eyes."

Fargoth nods solemnly along to the sad tale, although the large creature mentioned gives him pause for thought.  "This behir you speak of... would it be possible to drive it against the Hi-Thoror, thus aiding us indirectly in our plight?  What do you know of it and its lair?"

Looking to Brevig, Glint nods and says, "We can take you that far."

Nim, with a mild shake of her head, addresses Fargoth. "Long have I wished to trick the Hi-Thoror into entering that cavern. But to have the behir act on our behalf? How could such a thing be done?  We know a few passageways into the monster's lair. Those tunnels are large enough for us...and for orcs...to enter, but they are much too small for the behir. There must be another way in, one large enough for the behir."

"That passageway must be deep below," adds Rizzlepick. 

‘If there are only two dozen of the tribe left, I think trying to use the Behir introduces too much risk. I’d favour a frontal assault over that - but I think the back entrance is best, unless...’ he thinks a moment. ‘I can disguise myself, perhaps I could be an orc escorting one of you as a prisoner. We could then hold the attention of the sentries while the rest of the group arrives...’ he looks over to Nim, who seems to be the main spokesperson of the gnomes ‘Can you describe what the orcs look like, are dressed like? Or perhaps even show us to one of their bodies?’

Nim seems lost in thought for a few seconds. She then utters a few words and transforms herself into a miniature orc, replete with hide armor and a great axe. Around her neck is a polished band of iron; two matching bands encircle her right forearm. Three parallel lines scar her left cheek. 

"Imagine this a bit taller and smellier," she quips before abandoning the illusion and returning to her usual appearance. 

Brevig’s eyes widen in astonishment at the illusion, and he chuckles wryly in appreciation. “I am in favor of the front door, as you call it. Perhaps if I am the prisoner and Patrin a very tall orc, that part of the ruse is accomplished. But how to disguise the arrival of Gwin, Fargoth and Donir? Also...” he scratches his beard thoughtfully for a moment before continuing, “the tribe is small, a mere two dozen members who no doubt know each other very well. Patrin will have to be very careful about what he says. And suppose their leader possesses arcane powers in excess of his reputation which allow him not only to incite fear in his opponents, but to penetrate enchantments as well. How might we time our arrival to insure the most...receptive...audience is on duty, so that we can face Kridash as one, rather than divided?”

"I am not incredibly in favor of the approach where we attempt to infiltrate as prisoners. There is too much room for error, and if we are discovered we will most likely be worse off than if we just assaulted them. After all, if we were to be convincing we would need to shed our weapons and armour, leaving us heavily weakened should we be discovered. I would prefer a similarly silent approach, but one where we just attack them unexpectedly after sneaking in, no subterfuge necessary. If we must fight our way through a few orcs, very well, but I would still consider it less risky."

‘Maybe we keep it simple then,  go in unsubtly through the back route and force a number of smaller battles...?’