The ones that annoy me are sometimes there's a mercenary unit requirement. And I never use mercenaries otherwise, except perhaps in extreme emergency cases where I'm trying to extract a beat-up army from a bad situation, and then I only keep 'em for a turn or two. So I just leave the mercenary thing to the end, and just hire a bunch to meet the victory condition. Even then I kinda begrudge having spend money on those bloodsucking rascals.