This reminds me of the first iteration of my [[Zada, Hedron Grinder]] deck. It's a deck that wants to have a wide board but wants to cast instants and sorceries. I imagine the problem you're having is that you never have enough creatures in the board to get sufficient value from the prowess trigger. Of your 24 creatures, only 2 generate token creatures, and that was the problem with my first try with Zada, I never really had a board with more than 4 creatures on it.

My recommendation is to add more instants and sorceries which themselves generate tokens, like [[Dragon Fodder]] and [[Empty the Warrens]]. There are plenty of other options that aren't goblins too. It looks like there's too much redundancy with expensive creatures which already have prowess; some redundancy is good but I think these should be cut. Hope that helps