If I'm moving at mach 2, how much weight I can lift isn't going to do much to change how hard I can hit. Whether it's 75 tons, 50 tons, or 10 tons, a man-sized projectile moving at mach 2 is really gonna hurt. Having 100 ton strength isn't so I can hit a bunch harder than any other character, it's just to give me one or two more options besides "punch" and "blast", like throwing vehicles and tanks and such (which admittedly won't ever do as much damage as a mach 2 punch, but I like to keep a few options open). It's like Melon (I think it was Melon) was saying earlier. How strong you are doesn't determine how hard you hit.
Freedom can hit just as hard if not harder, since he's a bit faster than I would be, and he's clearly not OP for a high-tier since Fury beat him. The only difference is that I'd be able to throw bigger stuff and beat him in arm wrestling.