>>37585619>>37585634The reason its the other way around is for maybe less-than-obvious reasons.
Rage is way better in oldgens, so Rage gets you through early game very easily until you hit ice punch, strength, and surf, where having good attacking stats and one of the best STABs in the game carries you the rest of the way. Having the strongest Earthquake of the three starters is also a huge help late game.
Cyndaquil does a lot better in gen 4 since Bugsy is a lot harder, then after that you pick up Fire Blast in goldenrod (which isnt available in gen 2) which is a huge power spike that carries you despite otherwise being mostly worse that Gatr.
The gen 4 speedrun does eventually ditch the starter for Raikou, but the only reason the gen 2 speedrun doesnt is because you cant do rng manip in gen 2.
I guess this implies that speedrun strats = optimal for normal in-game playthroughs, but thats a different arguement if you want to object to that.