This isn't even about merging vs. polarizing. That discussion would be about whether we'd rather 3-bet ATs or 65s here, and that depends on what hands he's just calling our 3-bet with. But to say ATs is one of the worst hands to 3-bet is just wrong. Even if he has a tight 3-bet calling range, ATs still outflops him more often than most junk hands like 94o.