Ill set the scene.
CJ comes out of the barber shop with his Mr T haircut. He is stoked and goes to pick up his big van that is freshly painted like the A Team van. He arrives and notices the van is rocking. He opens the door and Tommy is banging all of CJs girlfriends at the same time. Tommy sucker punches CJ and takes off in the Van. CJ comes too and hears Tommy tuant him into a fight. CJ then jacks a car and the chase is on.
Fully buffed-out CJ doesn't have any fighting styles that kill in less than 5 hits(except for kick/stomp, but that doesn't count because Tommy can do as much damage with his kick). Compare them both and you'll see what i'm talking about. In a gunfight, i'd have to say CJ(Jetpack + Auto-Aim) though they would all be good fights nonetheless.
EDIT:
Your basing it on your own conclusions and not on evidence from the 2 games. I tested both of the games, Tommy is stronger because he kills faster and in less hits.