Try swapping out Dragon Fodder in favor of Mogg War Marshal. MWM's casting cost (which is the same as DF's) can be lowered by Goblin Warchief's ability. It can be searched for, via Goblin Matron's ability, while Fodder can not. And on the next turn after you play MWM, if you opt to ignore his Echo cost, he still replaces himself with another 1/1 body anyway. Thus, if you have a sac outlet in hand, i.e. Goblin Grenade, you can play MWM, immediately sac it to the Grenade, and he'll immediately replace himself, allowing you to still have the same number of goblins in play as before you cast the Grenade. Not to mention that that extra token coming into play, when MWM dies or gets sacced, serves as another trigger for Impact Tremors.

Tl;dr version: Play Mogg War Marshal instead of Dragon Fodder, because at worst, you'll get exactly the same for the same mana cost, but you may get more for your mana, and it has more interactions with other stuff in the deck.