Improbable Weapon (Ex): At 1st level, the battlefield tinker learns to create a unique invention, cobbled from various weapons to suit her unique specifications. The battlefield tinker chooses one weapon or shield with which she is proficient. She may add up to two other weapons to the chosen item. Each weapon acts as a mode for the improbable weapon, being wielded and dealing damage as that weapon. Modes may be switched between as a free action. The improbable weapon requires as many hands to wield as the largest component weapon (so combining a kukri, sap, and scorpion whip counts as a light weapon, while a longbow, greataxe, and longspear would require two hands). If any mode occupies a hand, that hand counts as occupied for all purposes (such as spellcasting or reloading a weapon) while the improbable weapon is in use (so a buckler combined with a pistol and cestus would occupy a hand as a pistol). Each mode is treated as a different customized weapon set for the purpose of how it interacts with armiger class features. Each mode of the improbable weapon grants an additional talent at 11th and 19th levels. An improbable weapon can never have an additional weapon or shield added to it via improvements.
I thought to check this since.. well I had a particular idea in mind relating to it but it seems improbable (pardon the pun) with this ruling
Sword and Heavy Shield as mode 1
Great Axe as mode 2