CMP should mean CaM Position sensor
Yes, it is used to fine tune sequential fuel injector timing and spark advance/retard
But it is not "required" for engine to run on most engines
Early fuel injection engines used Batch Fire injection, one step up from a carburetor.
Sequential injection could be done with a Crank shaft sensor, but was more accurate with Cam sensor, a distributor IS a Cam Sensor, same/same.
Cam sensor will give better MPG and lower emissions.
Crank(CKP) sensor is still the main sensor, engine will not start/run without CKP signal pulses.
CMP fine tunes CKP pulses for best MPG