You have the right person.
The CIM is still a great motor for FRC. There is a saying I have heard in the DC motor world where Power is cheap, but torque is expensive. The reason being a low speed high torque DC motor tends to be extremely expensive compared to a high speed high power. What do you do? Add some geartrain… which last I checked is very expensive and relatively high loss in FRC (compared to high efficiency industrial or transportation drives).
775 Pro is a great motor, but you have to be very smart about using it. Much like the 6 motor drives:
this season I have watched 2 3XXX teams have a successful first half of their season, already played in 1 district, and then at the second, start popping Main Breakers during elims. Why? Teams were getting good enough that defense starting coming into play, which caused higher draws, more low speed maneuvering, which in turn pulled high currents. Later they implemented some current control SW and were back into good shape (Thanks CTRE for the capability).
I then saw at Wolrds a sub 1000 number team pop their main with their 6 CIM drive for the first time (after 2 districts, a regional, and a State championship). Why? they played harder defensive than ever before trying to shut down a scoring powerhouse. We talked and they replaced the breaker and added current limiting controls and I believe they resolved their issue for the following day, but they had the World Watching when they died in a match…
With a bot-load of 775s, not only do you have to be very careful with your Main Breaker, but playing defense, there is a pretty decent chance you might frag a motor as the motor fans do not move much air at low speed, and the currents are really high. If you are planning on this set-up, better have a solid solution for helping your motors breathe better.
Now, if you have the capability to solve these and a few more differences, then I think doing a 775 drive is an excellent idea. Just remember, all of these new efforts result in new work, which without new resources will pull resources from programming Auto routines and state machines, pull mechanical design of a manipulator for coming up with different ways of gearing and controlling motor heat. $$ you would normally spend on scoring buying additional gearboxes to make sub-assemblies so that when you do fry your motors, you have a whole set of spares to swap in…
I still think it is a really cool and potentially amazing set-up to pursue. I just hope teams realize, it is a more difficult set-up to get right. Remember, that when intentionally traveling a harder trail to follow, it will require more effort to get you from A to B. If you have the resources and preparation, you may experience a richer, fully trip with beautiful views, but you could also twist an ankle, get lost, show up late to the rendezvous, or end up with poison ivy.