Even though I get why the Scar/Lex team up bugged people (it's like Jason teaming up with a camp counsellor), I thought it added some nice variety to the interaction. I wouldn't want it in every movie, but yeah, I liked it once. And as for the Wolf, I think he was just preserving their human preserve, not helping them. He kills several people for no real reason. Now, part of that's just shoddy writing (why skin the cop?!), but he really has no purpose besides containing the xenos. A lot of people get killed who are in his way.
And the P1S in Preds was going to help Royce get home. I really liked that. It would have enraged me if he just magically figured out how to fly an alien spacecraft. If he'd gotten on it!
But anyhoo, yeah, I agree with the OP that the sbp's were nice to see in psycho killer action.