In theory, yes, they can know that the other is part of the group, and peripherally even know where the other is positioned and doing, but the important part is to refrain from using that information to influence either character's actions.

Huan: [Seeing that Curufin was on the left, Huan decided to go right.] <---Not Cool D:
Huan: [Seeing that the other group was on the left, Huan decided to go right.] <----Cool :3

You would also need to avoid things like having them doing something "off screen" together. For example:

Huan: "I did this thing with Curufin earlier today, so I know what's going down." <---Not Cool D:

Like I said, it's tricky to pull off if they are part of the same group. My suggestion would be to not have them fight the same werewolf / group of werewolves at the same time.

Does that answer your question?