The Mechanical Golem/Machine Golem one is very cool, thematically. It could use a buff though, reattaching takes 1 turn, but a delay for the first detachment, and only gains +1/+1 per turn. To use it as a creature pool, you only get 1 per 2 turns, using 3 of the 4 to balance the 2 detachments. However, it is capable of being applied to other creatures, not just the Golem. I suggest making the Droids get 3/3 and the golem gains -4/-4.