I'm doing a few small changes to the revive system, as well as reducing the Rogue's hp:
[*]On revive, players will recieve a 50% speed boost and period of invulnerability for 6 seconds.
I think that reducing rogue hp wouldn't be as effective as decreasing their damage output. If anything, I would say increase their hp but decrease their DPS. The hide, attack would make it nearly impossible to get the flag with a bunch of gnolls hiding around it.
Recieving invulerability is a good idea after a revive, but isn't 6 seconds along with a speed boost a bit too long? Considering how fast the heroes attack in this game, 6 seconds is more than enough time for spawning heroes to move to the enemy and land a few hits before they can retaliate. I would suggest invulerability but no speed boost. Or perhaps a shorter invulerability period.
Suggestion: Maybe a life mode, once you die, that's it until the next round.
IMO, heroes attack so fast that its hard not to die. This mode would make gnoll rouges be even deadlier. Simply camping the flag until the opponents run out of heroes would be the strategy.