I was thinking of a system where after importing from the armory you are asked what each WoW rank should translate to on your site. IE:
Imported Rank 1 is automatically promoted to site rank Guild Master. Rank 2 is Officer. Rank 3, 4, 5 are all promoted to Member, etc.

Maybe have it ask each time you import or have a new section that you can set the defaults in prior to importing.

This is something I've given some thought to because it absolutely makes sense to have rank bindings of this nature. I just haven't done it yet