To be honest, in my opinion, we should keep 3 servers, with one of them being Buildbox. Let's face it: Buildbox is more of a necessity than all of the other servers, because it is what supplies them with the maps that they need. Sure, we could just get rid of it and make players go on single player or create their own private server have to download WorldEdit, MCEdit, and all this other crap to make the map they want to make, and send it in, but Buildbox gets rid of all of that hassle. If we got rid of it, I guarantee you that the number of map submissions on servers will go down TREMENDOUSLY. In that sense, I think the "two servers we should keep" should be servers other than Buildbox, and have Buildbox stay there to keep the other 2 alive.
But that's just my opinion, of course~