1) So I fire up 2000 nodes, all selecting 200MB as cap.
2) I make the miners belive this is the prefered block size.
Why do you believe that miners are really that stupid?
My point is that it opens up to sybil attack. My suggestion is obviously a quick and dirty model.
Okay, I agree with that.
EDIT: How would miners actually know what the "real" consensus is? Ask around on the forum? What if I set the blocksize to 14MB. That would still knock off plenty of nodes.
See my post above.
I think I read somewhere a Peter R post where he suggested the case of miners with BU sticking with 1 MB for a while. Then (especially when there is fee pressure) one brave miner might deem it worth the risk and try 1.1 MB to see what happens. If "nothing bad" happens, other miners would likely follow. Extrapolate from there.