Ash is literally a default name suggestion for Red, and, notably, sometimes Red
isn't
. It's completely possible for someone to play Pokemon Blue and never see the name "Red" in-game a single time. Ash (anime character) is not Red (game character), but Ash is definitely a valid name for the guy you control in Pokemon Red Version.
"You're childish. What are you getting? Are you getting strawberry? Ha! That's such a childish flavor, only children eat strawberry."