Once again, where are you going to seat them all? each judge needs space around him, away from anyone else that may cause distraction. These guys are gunna be sitting right on top of each other which will then lead to allegations of collusions on cards. There is no way this system can be practically put in place even without factoring in the additional cost which would cripple a lot of promoters
Why change something that has worked for decades on the back of a couple of dodgy decisions. It doesn't matter how many judges you have fighters will occasionally get jobbed