You can write a wall of text and that will not make your statement less false: "named slices" are not some entities which are hard to control, they are simple pools run on a few servers. Those servers serve thousands of real miners, people that invested hundreds of millions of dollars in their equipment, people that spend electricity, people that are real flash and blood of bitcoin network. "Named slices" can go up or down in their network percentage at the whim of the miners, and that already happened several times through the life of the bitcoin. And it will happen again, those names that we see on that chart will probably not be there in a year or two. Those handful of servers each pool consists of provide healthy competition for their services to the miners, if that was not a case we would not have 0-fee-pools we have today, and if any of them ever starts to misbehave it will go down in hours. There's no reason we should worry about "named slices" as you call them, they are by far most easily controllable part of the bitcoin community.
Ok. Less text and more pictures. Here is MegaBigPower, located in Washington State. He is a single miner in the Unknown pie slice chart whose ambition is to control 10% of total Bitcoin hashing power.

Here is infamous mining equipment manufacturer kncminer. This is a single miner in the Unknown pie slice chart whose ambition is to compete with customers still waiting for paid-for equipment. Proof-of-Work manifestly encourages bad behavior.
