Trash mobs in instances can include minibosses that require you to do some simple strats to migrate damage (ex. interrupts, moving out of stuff/beam type attacks, moving out of range of AoE from mini-boss, killing a specific mob first so mini-boss doesn't gain stacking buffs), and as a reward, both mini-bosses and trash mobs can drop EoJ's, phirius tokens, etc. Of course, the number of trash mobs should be reduced, since the goal isn't to make the instance take longer to run.
Drops should be scaled, so HM drops more items, easymode only minibosses will drop any items and also drops much less.