EOS and Bitshares don't simply have 21 mineworkers. It's a rundown of the best 21 that are permitted to create squares. However, they're picked out of a bigger gathering. So the main 21 can change amid the day. You may see 30 or 40 BPs making hinders on a solitary day. What's more, the BPs on EOS have level with vote. So they can't gain to 49% power, include some additional hash-power and attempt to get at 51%.
A hazard for EOS and additionally Bitshares could be that 1 aggregate fakes to be various distinctive BPs. Yet, that would cost an outrageous measure of cash/voting power.