No, I think it's because the green energy cards do two things, and only two things: Make a ton of energy, and then spend that energy to make creatures bigger
in the right scenarios, this card can be used to finish off the opponent on the spot
His built-in Sylvan Library that mills the bad cards out of the way is going to be great to set up your draws
Like the Monarch token, but actual cards
This cheap alternate win condition looks trivial to pull off with cards like Chasm Skulker / Toothy, Imaginary Friend + lots of card draw, Forgotten Ancient soaking up counters just by existing, and Vorel of the Hull Clade / Pir, Imaginative Rascal / Doubling Season doubling counters
Peach: Im not keen on the black in Maverick at the best of times, so Im not inclined to try this