Marvel just can't decide what a "mutant" is. Submariner was a mutant because he was a hybrid,That japanese guy was a mutant because his parents genes where altered by an atomic bomb, Sam Wilson was a mutant at one point due to bhis connection with "redwing" his bird. Then a mutant was supposed the be someone who came from a long line of genetic potential only, not a wierd expariment or anything just that is was genetically ment to be given enough generations.