>>47320056>reflecting, lightscreeningThe problem with this is there's no reason to do this in normal gameplay. It's helpful for doubles but that didn't exist in Gen II and even in HGSS it's barely present.
>synthesizingAlso not helpful in a regular playthrough when potions exist and can heal for more.
>giga-drainingNot until halfway through Kanto.
>leechseedingNot unless you ditch the one you actually get as a starter.
>defensiveIts bulk is respectable but it has a lot of weaknesses and it has an advantage over next to nothing for the vast majority of the game. Add to that that Feraligatr has more HP and three fewer weaknesses and Meganium's status as the bulky one becomes a bit questionable.
I don't even dislike Meganium as a Pokémon but it is absolutely the worst in-game starter.