It's actually the opposite. Humans fare much worse at freestyle chess because they don't have any opening theory and are unfamiliar with the patterns that arise

It's actually the opposite. Humans fare much worse at freestyle chess because they don't have any opening theory and are unfamiliar with the patterns that arise from nonstandard opening positions. Engines don't care much about opening theory one way or another Source: am rated 2000 fide (partly because I struggle with openings)