With this logic though like 25% of all feats from the 1960s-1980s should be retconned.
The island feat is actually rather tame in comparison to some of the things they have had characters do.
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.
Can't view it on my phone but I guess it's about the Phoenix cocoon stuff?
If that is the case, namor was having a psychological breakdown during that time. Hercules himself forces namor out of it and that fought to a stalemate on land
Both times he has over powered Hercules has been underwater
First time is when Hercules and a group of avengers attacked him under a misunderstanding
Second time is when he used a cosmic cube to make water. He overpowers him but sees the fight as unfair then brings them back to land where they fight to a draw