Allow guild occupy single castle or village in PvE world
There are far more guilds than castles and if one guild would want to have a castle then there would be “PvP”
You always continue forward, but there will be curves before you reach the end of the road.
And where is the problem? As i know, Arena plan to add guild vs guild options anyway. And about not much castles- not each guild have to have one. Small guild could have some camps or villages, and big ones could occupy biggest castles.