Ab Placement in a Push/Pull/Legs Split

[hockeyplayer]

Hey, considering that abs have supposedly superior recovery rates and that they don't really overlap from other exercises... what would you guys think of putting them in twice in the week (assuming they were placed as far apart as possible within said parameters)?

I ask this because it would be most convenient to simply pair them with legs, however I find that exhausted legs make ab work almost impossible (weighted decline & reverse crunches etc). And doing them before legs would be... well it just seems to me one should usually start with somewhat of a compound movement. ie. You wouldn't have shrugs as your first exercise right?