Just for a while when difficulty is low. Multipool and Middlecoin togehther have 1800MH/s.

So to conclude myself pools like above mentioned have a tripple BAD impact on  a coin. First are Orphans, which i already explained, second is they are lovering the value of the coin bcs they are immediately dumping the coins, and third one is more psychological impact on rest of miners after they leave network with high difficulty, best example is ARG.