Fine as long as these huge Zerg Clans do not get any bonus over small clans just for having huge numbers, rewards for clan activity should scale with numbers. Small tight clans that are high achievers should be able to rank with Zerg clans who have 80% of their members inactive. Clan rankings should be based on total achievement points across the entire clan divided by their number of members. This way large clans can exist as the OP wanted but small clans can also be recognised for their achievement on an equal footing, pure membership numbers should not be a reward in itself