I have that exact combo too, + a MIDI Controller. I've programmed few sounds on Circuit, so I understand each macro. Then it's like having more machines in the OT, it depends about the Program Change you send.
I usually do not use the Circuit sequencer, I use the OT one, because I can p-lock the Circuit macros (and CC if you need). But when I think it's going to be easier, I use the Circuit sequencer. STILL, if I use the Circuit Sequencer, I can use the parameter locks on the OT.
The Circuit it's like adding 4 drums and 2 synths, and I still have 6 free tracks in the OT (+1 Thru for Circuit + Track 8 as master).