For me, it is what you want to experiment with. I have run one offense game plan, and one defensive game plan for some teams. Then other teams I have 6 - 7 offense ( run in/out, pass short/deep, balanced run/pass, WR pass, RB pass TE pass etc) and 5 - 6 defense (for and against run, pass, heavy pass, heavy run balance, blitz etc). Also such things as SG running, WB passing.
Just have fun, experiment, raise your Form IQ and recruit the best players.