The prisoners are very heavily trussed up in rope, so it's difficult to be certain. The most you can say is that you can't see any identifying features that would mark either of them out as being Wadim (e.g. long beard).

Referring back to the sketch, the hollow's roughly forty yards across, and the chief is coming from the curtain (where he's almost the full diameter away from you) to the tree (where he'll only be a half-diameter away from you). There are a lot of goblins gathered round so I'd say he's got some cover, yes - probably just at the level of a -10 penalty to BS since you've got a nice elevated position.

but of course you don't know about his smokebomb squigz