Law would be even stronger had he even pre TS level Luffy strength. So far his strength feats are only when he counter blocked Overheat (it just wrapped round his sword). Luffy pre TS was tossing boulders injured and Law hasnt shown anything like tht post TS
Law is like the Hiruzen of One Piece. So full of hax and the "strongest DF user" but in reality is outclassed my members of the brute strength class
That doesn't matter because Law isn't a brute strength fighter. Brute strength isn't the only kind of fighting there is, though it may be the most common. Look at Kuzan. He isn't a brute strength fighter, he hasn't shown the same brute strength feats as Luffy, but the way he fights works for him due to the hax of being able to freeze for miles at a time.
Same as Akainu. He has brute strength, but his fighting style revolves around the intense heat and destructive capabilities of his fruit overpowering his enemies' defenses.
Even Whitebeard is kind of the same. While he has brute strength, his fruit also carries a lot of hax. Whitebeard is an example of hax mixed with brute strength perfectly.
Against Law, nothing but pure strength will mess you up. If you just go charging in fist-first, that's how you get caught by hax. Look at Vergo. He thought he could just go charging in with his strongest punch, and he'd be fine, and he got caught by hax. A careless enemy, just for a single second, will get defeated by hax. That's what happened Jozu at Marineford.