Jolt II and Impact are better in some particular cases where you have a too unbalanced mana bar and the one you need doesn't proc. And every 3 Impact, it's like you had one free Jolt II, mana-wise.
Acceleration, same thing it's to lower the rng system and make it easier and quicker to boost the specific mana you want in order to balance the mana.
Impact and Acceleration both have the same purpose, helping to balance black and white mana according to their current state because of your lack of luck with one color.

I mean you can think they are underwhelming, but I believe they have a nice purpose already.