That goes without question, but do you think pre-timeskip Blackbeard (who fought with Sengoku and Garp), alongside his whole crew, wouldn't be able to beat pre-timeskip Akainu?
Akainu seemed to be coming with enough backup to handle the crew, so I don't think he surpassed Akainu before TS. Akainu is also pretty smart and overdoes things so I don't think he'd under do it if he thought he was actually gonna get a chance to fight BB. Post TS Akainu seems to have made some gains as well - and if he's the face of the "good guys" I'd say he might still be a threat to BB even post TS.