Bankroll is important in NLH to figth against variance.
However, at Omaha game you play with defined EVS for nut or semi-nut projects. If I put all my stack 5 times with a 17-cards straigth draw on Flop, the probability the straigth doesn't appear at any of the 5 hands where you putted many chips is very low.
That does mean bankroll is not so important at PLO, or it is as at NLH?