Law without a doubt is stronger, his abilities and intelligence has even caused him to be a nuisance for Doffy even though he's low on stamina, been repeatedly beat to a pulp, and left with only one arm. And the guys arm alone separated from his body was able to solo Trebol a top executive and cause him to commit suicide in hopes of taking Law with him. A nearly half dead Law btw, this guy has been overused and has lately been used as if he's the protagonist. Its like its been made so obvious that Law is >Luffy.
Interesting thought line, when Luffy sent Trebol flying with one kick, and Law only got Trebol because it was a surprise attack and Trebol dropped his guard in anger.
Same with the knife, Dolamingo dropped his guard and even then he knit his organs back together and smashed Law right back into the ground, then mocked Law.
And used as if he is the protagonist, is that why Luffy had to rescue him twice and Law has openly stated that he has complete faith that the Strawhats will bring down Doflamingo, not to mention every other person on the entire island believes the same.
Also the only reason Law is alive, is because Luffy shielded Law with one foot and Luffy and Doflamingo were able to perform kicks that when colliding cracked the entire mountain.
I said it before and I will say it again, Law is vastly overrated, heck just look at the entire arc, the Strawhats have van guarded a revolution that brought Doflamingo's entire organization down in a day, something Law wasn't able to do despite it being his life's goal.