From my point of view, there's no point trying to fix something that isn't broken. what is wrong with the zooks currently? or is this whole thing just a red herring?
Zooks aren't broken, but the USF lategame is. They're overly dependent on Jacksons which are unreliable on any map with a lot of shot blockers and tight corners, so Zooks with lower Rof and more reliable pen (kinda like a shrek-lite) would help fill the AT gap.
Perfect opporunity to see shreck blobz reign supreme once again.
With the AT weapon XP changes, removal of shrek snipes and USF's more munitions-heavy design and pricier Riflemen, I'm not so sure. RE blobs could definitely become a problem, but that could be fixed by giving them the EFA Conscript accuracy treatment. If Rifles/REs still have too much AI DPS, it could always be cut with by adding a dummy rifle to the squad.