Two Bodies, Lens Combo?

I'm getting my 5d2 back from Canon on Monday (it needed a pro cleaning after a seriously botched self cleaning attempt). It's been on the shelf for months while I just used the replacement.

I shoot a lot of events, not weddings or big parties, but volunteer events for my employer, school events (four kids in three different schools...) and the like.

I find myself swapping lenses way more than I want too, so think I may just start carrying both bodies with me when out shooting an event. One body will likely end up with the Tamron 24-70vc glued to it. For the general purpose, covers most of the things well. The other body will end up with the 70-200, 16-35, or the 100l, or 85 1.8; depending on the venue, event type, and ranges needed.

What body would you choose to put the 24-70 on? Why?

Between 5D2 and 5D3? 5D3's main advantages are much better AF, better high ISO, better servo mode, dual card, silent shutter. Do you find you need any of these for the type of events you shoot (e.g. servo mode for sports or live performances)? Do you expect a lot of shallow DOF shots? 5D3 has increased my keeper rate shooting primes with very thin DOF shots. If AF with the 24-70 on 5D2 has not been an issue for you, you can stick with that combo and use the 5D3 for primes and 70-200 where you need the more accurate AF.

Amirg, thanks! That makes a lot of sense. I certainly appreciate the benefits of the 5d3 and assumed to put the workhorse lens on it, but it makes a lot of sense the way you suggest it given the more accurate af helping the other lenses and being more a benefit on lager aperertures and longer shots.

Yeah 5D3 breathes new life to my primes