Vyndree-- Track your whole-group DPS while you instance run and compare your mixed and matched setups to a 4xGorilla/4xBM setup. You may be suprised. Better yet, if you are instance running, track how long it takes to clear an instance. I levelled almost exclusively through WotLK instances and kept coming back to 4xBM setups with 4xGorillas. A 3xBM,1xMarks team is pretty competitive once you start getting 3500ish AP on everyone, though.

I run Aspect of the Beast on my team, as a note. A fully pimped out BM Gorilla with Beast going puts out a lot of AoE DPS-- I generally only have 10-15% health left on the last elite during a pull due to all the Thunderstomp damage. I was 10%+ faster clearing instances with 4xBM and 4xGorilla than any permutation of mixed hunter specs and mixed pet specs. Survival is very underwhelming-- the mana regen is fine but it's easy enough to hop into viper a little more often. The gorillas' DPS isn't impacted by viper, so you can just keep on mowing stuff down while you regen.

All this may change post 3.0.8 nerfs, but probably not by a ton. Thunderstomp is just hugely important for clearing instance trash. The total group DPS output that is gained by a Wolf's AP buff is less than the damage delta between that Wolf and a BM-Gorilla... Sucks, but it's true. Trueshot is damn good as well, and it will eventually make going 1xMM,3xBM worthwhile (gotta keep the 4th gorilla, though!!) once you have a crapload of AP. I kept trying all these different configurations and just kept coming to the conclusion that 4xBM-Gorillas was the fastest way to mow through instances.