I have around 10 Mkas sites and 3 legitimate sites (over 50 original posts) that is on same analytics and webmaster. None of them are interlinked in anyway. It seems that once my MKA was hit by Google, it dragged down all my legitimate sites too. Every new site that i created do not rank well if they are in the same webmaster & analytics account.
I have since stopped using both of these services using my real email account.