Looking up to a major league pitcher is fine, don't say that you shouldn't idolize those guys and learn from them?!?
But you have to realize that they are different pitchers. Give Lester CC's curve and he might not be as effective, it doesnt fit his profile and arsenal. CC throws 94-97, so a breaking ball at 86 that bites in and towards the dirt is an effective way to strike guys out.
Lester and Lee are more crafty guys, I know Lester throws 94-95 when he needs it, but hes not the same type of power pitcher as CC. Slow, sweeping curves work well for those guys to offset low 90's fastballs and high 80's cutters.
Look up to MLB players, but know that they are some of the most talented players on earth, and what works for them might not work for you. And yea, grips don't make the pitch btw guys. Settle on one grip and learn to command it, dont constantly swap them out because one grip gets you another inch of break.