Hi Joe
No that's fine, leave as it is unless other Admins who also operate dedicated Member Areas have different opinions.
As long as Admins know that every time someone accesses the Members Area that there will be a corresponding log entry for the main site. As I understand your reply it becomes a simple math of deducting one from the other to work out the external hits on the site.
I'm sure that if the need arises in the future we could always ask you to make the changes you're suggesting.
Regards
Alan