no, no, no, dumb from the get-go. i'm an idiot
should have seen from the beginning...
obviously, the gravitational rate from both objects will diminish at the same rate from their respective C's OG. if both gravitational rates diminish at the same rate, the additive result at an exterior point (in relationship to the line drawn by the orbit of the bodies around each other) can never exceed the maximum gravitational rate of the bigger body.
in this case, that can never exceed C, or the bigger body would "singularize".
dumb, basic math error.
my regards,
mrpex