"That is a lot of undead. We managed 6 with little difficulty. But three times as many? We probably should avoid engaging unless better prepared."

"Perhaps we could lure a portion of them away from the rest, whittle down their numbers?"

"Luring some away while not drawing the attention of the whole pack would be difficult I think, unless of course you have a suggestion of how to do that."

"If we split up and someone fast baits them while the rest try to pick at them from the back, perhaps some separate. Though, I'm not sure if one of us sufficiently more mobile than them to pull it off safely. Alternatively, it might be a better plan figure out where they are heading or came from, undead rarely rise on their own accord." 

"This might also be only part of an even larger group. Or maybe sent by someone..." Brekka muses as he watches the tracks of the shambling undead.

"Where are they going?" he asks, trying to discern their heading.

((Do we recognise the direction they're heading? Any landmarks in that direction we might know of?))

In case I wasn't clear, you don't see the undead, only a lot of similar tracks that moved in one direction, you are not sure how long ago.

The undead were coming from the direction of a set of low hills in the forest. You don't automatically know anything more about their direction.

To know more: (Separate pieces of info for each check. I request that each PC choose only 2 skills to roll at most. History and survival have the most pressing info.)

DC 20 History check;
DC 15 Survival check;
DC 10 Perception check;
DC 15 Religion check;

Kaelen checks- history: 12, survival: 14 -.-;;

OOC: Sorry, I misunderstood what we saw. I've edited.

Religion: 6
Perception: 16

Asariel: 

Perception: 18

Survival 14

Arista, History 6, survival 4. 

So far, you've only established that these definitely were ghouls and ghasts from the smell.

[[Perception: 11  Survival:  12]]

Arista notes that with that little information, they are better off continuing on their way, and just leave the encounter as an item on their list of things to report. 

You have the information I've given already, and you can attempt to follow the trail for the large group's origin, or where they went. This failed rolls were for in-place information, I'd ask for new rolls if you started in a direction. Or you can note this possible danger down and continue back to Threshold.