Page 15 of the Registration guidebook clearly states:
"In addition to registered unit positions, the following functional duties or roles can also be assigned to registered adult leaders."
This quote reads that a functional role (Advancement Chair) can also be held by a registered leader (SM, CC, etc.). There's no misreading that.
Please don't misunderstand that I'm not trying to convince, but instead seeking clarification. Surely based on the the above one can see how there is clearly room for interpretation.