While you could totally pay the expensive retreat cost to swap Weezing out, if it's your Active Pokmon, that's mainly what you want Koga for
Even now, while I think he's good, I don't think he's at his best in mono-sphere, because with that statline, while versatility is nice you really want to get some Unexpected Courages onto the table, so as an intended mono-sphere card I would say he was not well designed for his archetype, especially not at the time of his release
And then we have full playset of Birds from Beta as well as an Illusionary Mask GD) and a Word of Command (PL)
While the effect only triggers once per turn, since cycling can be done at instant speed, you can get four triggers of it in one turn cycle
Tokens are also an important resource in the late-game as you start to lock down the board
Metamorphosis Fanatic Metamorphosis Fanatic is a fancy way to improve on reanimation