One thing to keep in mind. If you give your officers the quals they need , they will green out a compartant. Torpedo etc.
As for petty officers 2 -3 for radio /sonar men 1-2 for watch and at least 4-5 repair. I learned this the hard way. Had a 40 plus career go down the tubes because I could not keep up with a bad leak. Even with a officer and 1 petty officer with Repair quals.
Plus if you play with commander you will lose people as you go along.