Just a thought... people can change nicks easily enough. If someone realizes you are auto-opping anyone with pro| in front of their nick, then they can leave the channel, change their nick, rejoin and get ops, deop and ban everyone else and change back to their own nick.
Granted, if you have chanserv/nickserv, or similar services, you can manage to recover from such an attack. But, it's a waste of time when you can avoid it.
