Your information is incomplete.. and partially bunk. tick rates do not need to be separated by others. Separating your player base over 3 different viewing resolution modes just does not make any sense... everyone should be playing in the same pool of servers. Otherwise your pool of 4k players would be extremely small.
The tick rates TO the server need to be consistent, so the tick rate is probably 20-30 times a second because the base game runs at that performance level. You could probably program the server to accept faster ticks and simply work with the users with slower tick rates, but considering we are talking about shiat tier network coders who have almost no cheat code protection, I am not going to give them that benefit of the doubt.
So if your outgoing tick rates are only 20-30, your incoming tick rates will never be faster. They COULD be slower.. but anything slower then 20 would be noticeable.