If you have access to the desert you could pick up a Trapinch for an eventual dragon type. Numel and Torkoal can both be caught from Fiery Path fairly early too, if you want a fire type. Makuhita might be a solid choice too and he can be found early on in Granite cave.
You've got decent HM coverage already between Wingull, Lombre, and Mudkip so personally I'd replace Zigzagoon with someone else. But that's just me.
Not to mention the massive difference in age between BG3 and OSRS/RS3. RuneScape's running on an engine that was never built with more than 2 body types in mind. Changing that is probably a much more monumental task than OP realizes, the armor models being just one (big) roadblock.
I'm no Jagex defender but I feel like the fact that they added even this small change to a 23 year old game's character creator shouldn't be labeled lazy. All that will do is discourage developers from trying.