A little change for the berzerker rounds may help you get it done in the time limit. Depending on number of subs you have you can get 24 hits per person (counting Zeke as hits) with 2 subs in those rounds. Lead off with Flav to wipe out the bosses morale. This is the form I run and with a couple good crits from Lance you can kill cerb/baal yourself in the last rounds.

XXX XXX Flav
XXX 1 XXX
Lance Zeke Main
1 being weakest hitter dies right off followed by 2nd and 3rd weakest