Instead of a grabo, i would put in a shield, or drain/vampire (for EM).
This is only if your 4 grabos are safely killing the opponent (i didn't calculate that).
I guess, if your tactic worked (and you worn the enemy's quanta down) you keep them unburrowed anyway.
Otherwise, it seems to be a pretty good deck, using time/earth and darkness/earth (for burrowing) and the cheap cards.