Well ... let's see. I didn't spend any time trying to get their volumes equal or mix them on this, it was just turn it up, pan each hard the opposite way and let 'em rip. If I remember correctly, each omni is positioned around the snare drum, so the drummer on the left side of the stage's omni will be picking up some of the right drummer's floor and rack toms (it's a very tight stage at that venue).
In general, Brian (he's on the right side of the mix), plays harder than Tony does, Tony barely moves his arms sometimes. There's no active "you be Billy, I'll be Mickey" vibe happening to my knowledge, but since Tony tends to play more passively, Brian tends to play a little more actively.
Each has their strengths ... Tony is very good with dynamics (although he never gets really loud), he's also good with little odd accents, like hitting a bell at an apt moment, grabbing a xylophone or some shakers, and so forth. Brian has better meter and is a more straight-ahead solid rock drummer. When we go with one drummer, Brian is more steady; you can play to Brian, where Tony plays more to you, if that makes sense. Brian is also much more of a student of the Dead than Tony is ... Brian's doing those Mickey-like 32nd tom rolls on the "gotta go to Tulsa" verse, for example. Tony is also prone to occasionally doing something weird and out of the Dead drummer realm, like playing a "freight train" rhythm on a snare all the way through a tune like Maggie's Farm or Cumberland. Usually a well directed glare will deter him. But not always.
We occasionally have some good drummers sit in for one or the other, and then it typically does become a too-much scenario, much as it would if Billy were to try to play like he did 72-74 with Mickey in the band. I think overall, Tony and Brian do a great job, but there are these little flareups. Complicating the issue is Jimbo, our rhythm guitarist, is also a good drummer and very much a student of Grateful Dead drums, so he likes to try to direct, even on stage, which Tony hates. LOL
Listening to this, I wouldn't say anyone's really dominating the drum conversation here.