Its hard to complain theres simply too many cool heroes and villains running around, given they can technically be combined with other MTG cards for greater synergy (and I suspect this is intentional, to inspire further exploration for new players)
While I guess you could try to flip it into a 3/4, and that might be the right line in some situations, I think there would be decks (at least in Standard) that would play the front side as a sorcery
These draw inspiration from the Avatar: The Last Airbender intro sequence, putting the spotlight on each of these characters
Up to 160 HP can be restored in a single turn, which isnt unrealistic thanks to top-tier energy accelerators like MI Vaporeon and Manaphy, which can distribute Water energy to multiple Pokemon simultaneously
But theres another interesting twist to -1/-1 counters that also make these engines better: Green offers some efficient creatures that put negative counters on your own creatures as a drawback