For Each loop, or manually sorting through a counter
but
You can do this:
Every 1 second>>>
Enemyslime coinflip == 0>>
set Enemyslime.Coinflip = random(1, 3)
Enemyslime.coinflip == 1>>>
set toggle to <left>
Enemyslime.coinflip == 2>>>
set toggle to <right>
see if this starts choosing them better.