>>55453387Venusaur can win basically any fight with toxic + leech seed...but blastoise can win those fights way faster with surf + blizzard. Not the best. Victreebel shows up early and is pretty good, exeggutor shows up late but is eggxellent.
Meganium speaks for itself. Not the best. The only other half-decent grass type around is jumpluff, but you don't really need one in Johto.
Sceptile is pretty solid once it gets leaf blade but being stuck with fucking ABSORB until then kills it, to say nothing of how good swampert is. Not the best. Breloom and ludicolo are also solid.
Torterra is actually pretty alright, but infernape is nearly swampert tier. Not the best. Roserade is plenty good enough if you feel like you need a grass type.
Serperior is the weakest of a weak trio. Only ok once it gets coil at what, like level 40? Not the best. At least it's good in pvp. Whimsicott is pretty alright, but you don't really need a grass type.
Chesnaught and mega venusaur are good, but the water boys are better once again. The mega charizards are also better. Not the best. XY has a huge dex, there's probably a good enough grass type or two in there.
Decidueye is the weakest of its trio, primarina is extremely strong. Not the best. Grab a lurantis or something, idk.
Rillaboom and meowscarada seem pretty strong but I didn't play gen 8 or 9, maybe they're best?
So unless the monkey or cat are excellent in game, grass is never the best option.