I agree that a timer should be enforced for inactivity. 20mins would be good. As well as queues to give some idea of how long you are going to have to wait.
Is this more of an issue with available slots? If there are only 40 slots, should more than 40 people be able to have a character on that server?
Don’t get me wrong, I completely understand people will come and go or new friends\recruits will want to join you on the server you are already on, but if the cap is a hard 40 at one time, and who’s playing is constant during main play times, what makes the most sense? A timer does not fix a potential larger issue but there should definitely be something that kicks people who are not actually playing.
For Example: 4 x 10 person clans on a 40 slot server, who all play during the PVP allowed times(why wouldnt you 
). The clans try and recruit more people that go beyond what can be on the server at one time. PVP time starts but clan 1 has 15 people on, clan 2 has 15 people on and clan 3 and 4 can only get 5 people on or one clan cant even get anyone on. The people that are on are not afk. PVP starts and clan 1 and 2 wipe out 3 and 4 because they couldn’t get on. This is not an afk timer issue this is a server limitation issue. Potentially a large enough clan can lock out other clans from playing on a server if they coordinated with their members and worked hard enough. afk timers or not.
Whats the real solution? You cant remove the hard cap because of performance issues. You don’t want to limits friends from being able to join other friends or clans (of course this doesn’t matter if they cant get on). Will it balance out over time? What if clans want to grow larger? If the server is already maxed out during prime play time what would be the point of recruiting new people?
Is it just me?