Popping off 2-3 aoe moves will keep hate off a healer in most dungeon situations where people are single targeting and the tank isn't over pulling for single target kills, unless they (the healer) is dpsing a mob that the tank isn't paying attention to and isn't following the marked mobs.
Also hate is less of a problem from single targeting DPS when their attacking the same mob due to the fact their hate generation doesn't build up as high due to doing less damage, if their both putting out the exact same dps, they'll only build half the amount of hate they would have if they had taken on a mob alone, which means they'll be less likely to steal a mob off of you as long as they keep focusing down the same mob.
Ex:
Mob has 500 hp.
Only 1 player hitting a mob = they'll do 500 damage = 500 enmity max.
2 players hitting the same mob. Perfect situation where both of their DPS match will have them do 250 a piece = 250 Enmity when the mob is dead.
250 enmity is less than 500. Them both focusing on the same mob = less chance of either stealing hate, which is why marking is a thing for new tanks.
