3x of any class will be relatively poor because the game is designed from the bottom up to bring in different roles and group buffs. Bards are a good focal point of that, virtually every 3box with the same class would benefit dramatically from replacing one of them with a bard. Stacking the same class was pretty strong when they added alliances (I did 3x berserker + war + brd + bst in this era, it was great), but alliances haven't kept up with mudflation.Which brings me to a question I've had for a while, what's the best trio of the same class for DPS? Like if I was running an SK/SHM/BRD trio and decided to fill it out with DPS instead of mercs (provided the SK is geared well enough for the shaman to have heals well covered). What would be the best trio of the same class in that scenario? 3x Mage, 3x Berserker, 3x Monk, 3x Rogue, 3x Ranger, 3x Wizard? Or is a trio of differing classes always going to be superior? I would think 3x of the same class would be good for someone who wants less fuss, since controlling 3 characters at once to do the same thing would be easier. Hell, 5x berserkers decimating everything while you play a shaman and keep them epic'd and healed would probably be a pretty good meat-grinder group for a lazy person that could contribute to raids pretty effectively (assuming all of them could actually get geared up, and it'd be a project).
Presuming perfect skills, good 3x combos include necros and beastlords, mostly because they are both really strong right now and are self-sufficient in terms of mana and ADPS.
If you're looking for an easy box, it'd just be really hard to beat shd / shm / brd. All three are just so strong. A case could be made for replacing the shd for a war, since wars are very easy to play and you could just auto-attack and switch to brd / shm.