The Rocket is a special case. But in other accelerators, the accelerator is either on or off and the host CPU is either the opposite - off or on.
On my IIci with the DayStar '040 Turbo card, I can not use the '030 when the '040 is on. and I can not use the '040 when the '030 is on. The same is true I seen with other accelerators on other systems I had from the Mac Plus/512Ke to the IIci and LCs.
I understand that the Rocket is a special case where you can run as many as you can fit in concurrently, but with other systems you can't. It is either one or the other with most of them; not both.