Copper Golem should take from random slot of Copper Chest.

The first copper chest in my Golem-chain has many full stacks, but after clearing the first slot, Mr. Golem continues to fixate on that first slot, which is being dribbled items from a hopper chain.  As a result, he takes small handfuls of one item repeatedly, slowing his throughput to just a few items per operation.  If he picked a slot at random, he is almost certain to grab 16 of something.