A problem with this gonna be lore inconsistency lmao.
Gunblades were invented by hrothgar X Many Eons Ago, guns as in mch were invented by Garleans, reapery is an ilsabardian craft made by the losers who cant manipulate aether like races with actual souls, Scholasticism is a lost Nymian art, Summoning is straight up nonexistent beyond our job stone so how is the Manderville family in posssession of such armaments?
Unless it is all a joke and the weapons are just "old thing we have the WoL might find useful" which could very well be the case, but in such a case I hope we get Godbert or his wife's hammer/pan as a War weapon.