I watched some Championship warfare replays and quite interestingly Flavius did not look like he was doing the same flat rate against each enemy he hit.

US Season 2, Bubbaslab vs Dragonian.
http://www.tynon.com//replays/528153
Take note of the morale drain when Bubba's Flavius uses warcry. Dragonian's Flavius loses a lot more than the other heroes in his formation.
This suggests either a bug/glitch is in play or the morale drain changes depending on some variable.