Hey, just a suggestion which might have been brought up already. Could the owner of the site or a moderator create more sub-forums? A total war sub-forum to be more exact. I do think you would like to have as many members as possible would you not? By including other topics than just NW and BoF you would receive more members.
Atleast that is what I believe and which is one of the reasons why the TWC has thrived because its community consists not only of total war fans, but of Mount & Blade, Bethesda, Paradox and Minecraft fans. It does not have to be a drastic change, just first making one little sub-forum where people can discuss for example total war games, especially now that Rome II has been announced. It is just a suggestion I have been thinking about, and probably other people as well!