Garou and Baki should in theory have comparable technique mimicry, they can both obtain mastery over entirely new martial arts with a glance. Garou was able to copy WSRSF just by seeing it and obtain a master's level, Baki has able able to attain black belt level skills in a mere moment. However...
Garou was able to create the CSFDSF, a two person technique he's never seen, and is on the verge of creating the monster calamity god slayer fist. He can combine martial arts to create moves he's never even ever heard about to, IDK if Baki can do that. Plus, Garou can copy all Baki's stuff and unify the techniques, he could combine stuff like the Benda whip and cockroach tackle in ways that have never been done in Baki.
When I think about Garou's ability to synthesize martial arts, I think it gives him a major skill advantage- because he'll not only copy all Baki's techniques (Baki will do the same to him) but use them to create new forms of martial arts. Even if Baki can replicate the new martial art forms after Garou does them, Garou still has the advantage of getting a use or two in on unforeseen techniques.
I think much of Baki's arsenal- his pain manip with benda whip, his durability negation with cut cord and benda whip, status effect inducement, acrobatics, etc, etc, can be straight up copied by Garou. There are a few things Garou can't copy, but most of Baki's potential advantages will be negated when Garou copies them.
On the other hand... Garou's advantages, his superior reactive evolution, his resistances, his regen. Those are things you can't copy, so I think Garou's uncopieable advantages outweigh Baki's so he has the edge here.
