I asked this in the old forums as well, but I guess nobody is going there anymore, so before anybody gets a chance to answer over there, here the question is again:
That knockback+watchful combo ... in one BGG file I found overpowered marine comboes, one of them involved Big Guy (gain knockback with fists) plus Lean and Mean (gain watchful while having a dodge order). The suggestion was then that his marine could just juggle monsters around himself, repeat ad nauseum.
So, in principle that would be compatible with the rules? The same would go for a monster that had both knockback and watchful, if there'd be one?
(Personally, I find this incredibly overpowered.)