I wonder why Steem needs so long to confirm every account.... If they simply checked the account name they would know that these are spam accounts but their still approving such accounts!
I would suggest using a script that searches for users with similar user names. If someone wants to create "XY2" after they already created "XY1" Steem would see that "XY1" already exists and then don't create the account because it is highly likely that this is a spam account.