Seem's like the Ogre could use a few new long ranged attacks, that only focus ranged classes. Perhaps something like:

@ Periodic times the boss will target the "ranged" player with the most threat and cast a debuff on them, this debuff looks like a dome over the player, the player has 5 seconds to start running before the dome explodes leaving an AoE ground effect where the dome "blew up" and anyone in that ground AoE will take both reg damage + poison type damage.

@ Periodic times the boss will throw a buff on himself that increases his defense against projectiles, the buff last X amount of seconds. (This will help with the dps loss that melee have to go through to avoid damage) They could even do this with every AoE he does so that archers arent getting a huge leg up on dps.

@ Periodic times the boss will cast a debuff on any ranged projectile users, the user has to stop all dps or he/she will take the same amount of damage given to the boss. This attack happens fairly often.

Idk, probably retarded idea's but, if everything is so reliant on destroying melee, It should be the same for ranged characters. /shrug