Put a limit To Cops on duty (half of the players online)

A good way to "nerf" cops its putting a limit to the number of cops online, if the server has 20 players online, its very bad that 15 of them are cops, perhaps a good way to level this is by setting a limit of half of the number of players online.

Example: Sever has 40 players online, only 20 of them can be cops (still a lot but more balanced)

Maybe there are misspellings, I'm sorry for that, I think the idea is quite well understood anyway.