How about this.
On a Sunday of every month, the f2p wilderness has a cluster. The time will be at 3:00 PM EST - 8:00 PM GMT. Each month a winner is declared, based on clan fight topics & designated judges? For every new month, the cap increases 1 hour, making December a 12 hour fight. (Or you can just say uncapped)
I could go further with this if people wanted me to. Perhaps, find a way to make the fights a bit more fair.
Or na?