don't be delusional, really all it takes is 5 top pool ops.
If that happens it would turn out to be a tie, the longest chain would be in the new system but if the transactions aren't verified what good would it be? If the pool ops do that they risk destroying Bitcoins utility.
And Nodes can enforce the block size limit more easily than for example the number of coins since well in order to fill the blocks it takes transactions. Where are the mass of transactions come from?