This card is useful if you're running deck that purely focusing on fusion monster. I'm currently using KOG deck revolve around summoning Dark Paladin or buster dragon in the earliest turn as possible.
With balance skill, you are almost guaranteed to have your starting hand contains 1 spell card in 20 deck cards, if your 20 card consists of at least 5 spell cards.
(2) and with such condition, having only 3 polymerization is not enough to have consistency in those deck. To increase it, therefore other fusion supporting card is needed, like fusion sage, or fusion gate, hence making the spell card count to 5
No matter what you say this card is trash, literally just run another poly instead of this. It's a waste of space. Why would you run a fusion sage and a poly when you could run TWO polys.