Prologue- 3 of my closest friends stopped playing D3 long before any patches fixed anything (say up to 3 weeks after launch). I have been allowed access to to all 3 accounts, giving me a grand total of 4 accounts to Multi-box.
the Idea- take 4 of X class and run ubrs (or farm- slight build changes) runs my self. X class will be monk for me (since that's what I play on my personal account and have a fairly descent working knowledge of the class).
First, this will be just for fun and to see how well it does - def won't beat say 4x Barbs. Secondly, at present I don't expect the builds to EVER efficiently farm say MP7+, but for MP1-6 (prob around 3/4 will be ideal). Monk 2 will be sort of an exception for gear, focusing on items that will increase the fire damage output. Should also affect the Ally as well. If you take the time to look at each build you'll notice I use Crippling wave and Deadly Reach. FoT does provide more Raw damage, but when building I wanted skills that will benefit the group more as a whole.
I also wanted to avoid the standard cookie cutter monk builds (The TR speed run build or the Standard defense/buff up build). The ally's provide "extra" targets for Mobs, additional damage, additional benefits and give the class a change in flavor from the norm. The 2 major sources of Damage are Sweaping Winds and 7-sided strike. 7-sided strike is another good immunity from annoying combos like arcane or fire chains while providing significant damage.
Last thought before I submit- I'm fairly certain that to an extant these builds COULD be used solo (all be it rather ruff going), but will only really shine/work when used in a group setup.
@Glurp, your probably right untill all 4 hit paragon 100 (roughly the same time)- on mp0 that would be 375 (Nv5 included) mf/gf. Enough to find decent item, MP level will improve that % and their is plenty of great/decent items that include mf on them.
Right now I'm looking to grab 4 scorns with roughly same stats for 2m per. I know I know, You said you wanted to avoid cookie cutter specs, so why the skorn? Many of the monk abilities are based of the Weapons damage, not its/the monks DPS. This means Higher min/max damage range like the scorns will have the abilities hit harder. Though in the end I do think I'll end up with several inna's pieces.