Found out after I used Animate Dead that an animated skelly soldier has weapon focus and weapon specialisation battle axe...... but uses a long sword.
So it doesn't affect anything.
We make 1000+ npcs. We copy/paste a template and when feats have no effect whatsoever, i.e. using a longsword and having a bunch of redundant feat. We dont bother.
I might also add that Shambling Corpse uses an unarmed strike instead of claw/bite/whatever, and doesn't have improved unarmed strike.
Maybe just to simulate how lumbering it is, whatever. Makes it a funky summon, though.