(Yeah, they'd work too. Luckily, the rope needed only 5 points of damage to break.)

The ropes snap as Eldin uses his hidden location to quietly topple the crates onto the large warforged. Normally, I'd give them advantage to the Strength saving throw due to powerful build, but the disadvantage from not seeing this coming will counteract it.

Box avalanche: DC 15 Strength Saving Throw, taking 7 bludgeoning damage on a failure and knocked prone, or half as much and not knocked prone of a success. Carrick will need to roll one as well, as he is in the area where they all toppled (will roll alongside Warforged).

Carrick's Strength Saving Throw: 19
Warforged #1 Strength Saving Throw: 16
Warforged #1 Strength Saving Throw: 26

Carrick, while covered in boxes, is somewhat warded thanks to his spell. (Carrick: 27/54 HP, prone)
The front warforged manages to resist being knocked over, but the second one falls beneath the crates. (Warforged #1: 3 damage. Warforged #2: 17 damage, prone)

Map:

 INITIATIVE TRACKER

Eldin used his action and bonus action to topple the crates but he should still have his movement right? Can he move south and toward the doors?

He'd use 5 feet to get to the crates, so can scale down (5 extra feet of movement), and have 15 feet left to move South. Updated maps.

Map:

 INITIATIVE TRACKER

Carrick has no idea what caused those crates to fall on him, but he just throws up a bird.

(Eldin is a big strong Mercenary who needs no man. Doesn't care about collateral damage.)

After the noise/crash, Boo will fly straight up to the ceiling --air-- to find a gap/stop should the Warforged come crashing through... below looking to get above and over the fray. The general idea is for Boo to be looking as she moves to get a look at the crates near where the Warforged came from to eyeball crates that seem separate from the others, i.e. not in a stack but off alone or just separate from the rest, that the Warforged might have been guarding. Boo is looking to check if they are marked or can tell if they have shards, or at least if she can see a clipboard with this carriage inventory hanging somewhere towards the other end of the carriage... maybe, maybe not just wanting to see if the shards are even here if possible, if not they can decide if they want to retreat or not... or otherwise the boys can lead them away from Boo. Investigation/Perception 24 

Boo searches the area, and notes that there is a clipboard stowed in a little gap at the far end of the room, beside the doorway but with the pile of crates semi-obscuring it. Basically if you stand by the doors at the far end, you can grab the clipboard out of its holder. As for looking for a shard box, it is unlikely to be in the pile that just went crashing down, or they probably would've reacted badly to such a jolt. Checking the rest of the room, the rest of the crates appear to be tightly tied up and out of the way. Since they are a couple of crates deep, it is possible they are hidden against the walls, lining the carriage.

Map:

 INITIATIVE TRACKER: ROUND 2

Second Wind: 12

Carrick will burn half his movement to stand up and attack the Warforged.

Attack: 14 Damage: 8

Attack: 28 Damage: Unable to parse dice roll.

Action Surge! Two more attacks

Attack: 24 Damage: 9

Attack: 12 Damage: 10

Carrick gets up out of the crates, shrugging off some of the brunt he took as he strikes at the warforged. With a quick succession of strikes, the warforged blocks one with its heavy fists, but doesn't manage to stop the cut to the gut. Using the momentum, Carrick continues his strikes and manages to get another blow. The warforged looks moderately injured, but still kicking. Carrick's Blade Ward drops now, leaving him open to the attacks of the juggernaut. (Carrick: 34/54 HP. Warforged #1: 21 damage.)

Map:

 INITIATIVE TRACKER: ROUND 2

And since stealth is gone, Carrick is going to call out to his partners. "Someone wanna help me with these damn Warforged!? Preferably without dropping more crates on me!"

(I'm going to give them a little longer to respond. If there's not response in the allotted time I'll take over their characters to back you up.)

(Right, they've had their 24 hour period. I'll take control of them until they turn up.)

Edrick whispers words spoken to them by their patron, an external force from the realm of nightmares as it sinks into the mind of the warforged.
Dissonant Whispers vs. Warforged #1: 9 vs. DC 16 Wisdom Saving Throw, taking 14 psychic damage on a failure, and will have to move away from Edrick as much as possible, or half as much damage on a success.

Ith hurls a bolt of flame at the warforged who was using lasers.
Fire Bolt vs. Warforged #2: 18 vs. AC. Hit: 16 fire damage.

The warforged, unable to figure out the "logic" of such whispers, walks away from the party towards the back of the cart. Carrick and Eldin may make an opportunity attack against the warforged as it flees. (Warforged 1: 39 damage)

The bolt of fire hits the other warforged directly, damaging the unit slightly. (Warforged 2: 28 damage.)

The First Warforged, turning back to where the rest of the group is, sees Eldin near it. The warforged strides towards him, striking at its target with extreme speed.
Iron Fists vs. Eldin: 8 vs. AC. Hit: 4 bludgeoning damage.
Iron Fists vs. Eldin: 12 vs. AC. Hit: 9 bludgeoning damage.
Iron Fists vs. Eldin: 12 vs. AC. Hit: 5 bludgeoning damage.
Iron Fists vs. Eldin: 10 vs. AC. Hit: 4 bludgeoning damage.
Iron Fists vs. Eldin: 21 vs. AC. Hit: 4 bludgeoning damage.
Iron Fists vs. Eldin: 7 vs. AC. Hit: 7 bludgeoning damage.

The Second Warforged, seeing Carrick step up the attacks, does so in kind. It gets up from the crates and steps up to beside Carrick, unleashing a huge amount of blows against him.
Iron Fists vs. Carrick: 24 vs. AC. Hit: 6 bludgeoning damage.
Iron Fists vs. Carrick: 26 vs. AC. Hit: 9 bludgeoning damage.
Iron Fists vs. Carrick: 7 vs. AC. Hit: 4 bludgeoning damage.
Iron Fists vs. Carrick: 13 vs. AC. Hit: 7 bludgeoning damage.
Iron Fists vs. Carrick: 23 vs. AC. Hit: 7 bludgeoning damage.
Iron Fists vs. Carrick: 13 vs. AC. Hit: 6 bludgeoning damage.

Carrick takes a serious amount of blows into his body. He must make a DC 13 Constitution Saving throw or be stunned until the end of the warforged's next turn. (Carrick: 3/54 HP)

Eldin fares better, but still can't deflect all of the strikes that came his way. He must make a DC 13 Constitution Saving throw or be stunned until the end of the warforged's next turn. (Eldin: 25/40 HP)

(And yes, six attacks is correct for each of them. They're taking the training gloves off this time...)

Map:

 INITIATIVE TRACKER: ROUND 2

AoO with rapier: 19 Dmg:5

Eldin's attack of opportunity doesn't manage to pierce through the composite plating. (Also added the additional info into the post above. Please make a CON save, too.)

Eldin's CON save: 3

(Welp. RIP me.)

(Oof, technically that turns the second blow into a crit, which'll be another 3 damage.) (Eldin: 22/40 HP)

Boo glances back and down in horror to things going badly for her partners, she cringes as Carrick takes a hell of a beating while poor sweet Eldin has troubles of his own. Frightened out of her wits, never been much of a fighter or one to head into headlong into danger she does just that and flies straight towards Carrick ignoring the Warforged to hoping she can get to him to touch him and cast Cure Wounds 14 as her action on Carrick.

Eldin is unfortunately stunned.

Boo manages to swoop down to beside Carrick, letting her healing hands to their magic. (Carrick: 17/54 HP)

Map:

 INITIATIVE TRACKER: ROUND 2

AoO vs. Warforged

Attack: 19 Damage: 9