Edward
You do whatever seems best to you, you cannot actually go far wrong. Don't worry about me an Jazz, I like winding him up and he likes screaming obscenities at his computer, it's a match made in heaven, no lasting damage has been done.
"Tempted to run the cables all in one length". Does that mean bring all 8 motor wires back to the driver? I would say bad idea because you still have to join them, the wires do have resistance and there will be heating. If all together in a cable rather than loose in a conduit, there is not much scope for dumping excess heat. Running 4 wires halves the resistance. Also, beware cutting any wires close to the motor, leave yourself plenty of wriggle room.
Robin