Those moves don't really matter because Treecko just gets Giga Drain that his evolutions don't get. We all know Leaf Blade is the best grass move he can have because it's his signature and has a hit critical hit radio.

Sceptile@Leftovers
Crunch
Leaf Blade
Dragon Claw
Protect/Toxic

That moveset also works well as a Special Sweeping Sceptile.