Inf Health still affects enemy team so that their health resets after each round, if target gets stunned or fail all-alone roll the hp doesn't reset.
Also your own units can be taken out when they get heavy dmg during one round (for instance charge + 2 normal hits)
My own units hp shows a very small bar if it gets to 0, it's out of the fight, tho sometimes on next hit it might turn to a full hp bar.
I'v been playing on Skaven.