Have you been playtesting? How has it been? How often have you untapped with Yarok?
I've been playtesting several times. The deck draws little atention of the opponents because of the creatures affecting the board only on the ETB and then being just small blockers. Then eventually it wins by surprise, I won once by doubling the effect of
God-Eternal Rhonas and a couple of creatures.
Yarok does not eat a lot of removal, but that's because my opponents tend to play commanders more
dangerous than Yarok, so it's not usually a kill-on-sight.
At the end of the day, the ETB I abuse the most is
Spellseeker. Too bad she can't search for
Fabricate though.