Thanks @dubstepjoris for the detailed response!
To be honest, I'm hoping for the rig to be able to do a bit of everything. I've currently got a 6u Rackbrute + Minibrute 2s setup, which I'm planning on turning into a standalone synth for more beat oriented music, so this rig can be predominantly generative focused.
Good point about the trigger sources and quantizers. As @Manbearpignick says, I tend to use the O_c for shift registers and quantizing, so I'm hoping that the 2 there plus the Scales will get me where I want to go. Then again, I'm definitely eyeing the Harmonaig and a few others. It's amazing that with a rack this size, it still feels like I have to make compromises in places.
Thanks again everyone!