You've said your unit understands this to be a tradition where your Officers, Warrant Officers and Snr NCO's show their gratitude to their soldiers for their hard work, so how do they rationalize the connection with the guest, who in this case might be a guest that is really only an acquaintance and may or may not know the soldier well, let alone the unit?
Personally I think its bad idea, but recceguy's example is perhaps the best compromise.
Mixed mess functions are intended to show our appreciation to our spouses/significant partner. Non-mixed mess functions are meant to maintain a sense of esprit de corps and liveliness amongst the military members of the unit, and that's where, in a roundabout sense, the men's x-mas dinner lies. It is not purely the soldier's dinner to do as they please, there is a purpose behind it.
Personally I think its bad idea, but recceguy's example is perhaps the best compromise.
Mixed mess functions are intended to show our appreciation to our spouses/significant partner. Non-mixed mess functions are meant to maintain a sense of esprit de corps and liveliness amongst the military members of the unit, and that's where, in a roundabout sense, the men's x-mas dinner lies. It is not purely the soldier's dinner to do as they please, there is a purpose behind it.