[ZeoRangerV]

If you consider Gosei Mystic an auxiliary machine, then Tsubasamaru/the Falconzord should be under the same catagory. It isn't a transformation mecha, it isn't a pilot-able mecha and its main reason for to grant the main mecha a new power.

And it did do something for Muteki Shogun. It gave a robot that only could fight with physical attacks an artillery and the ability to do long range attacks. You're calling it an already powerful mecha, but you have to remember that it's the base mecha of Kakuranger, not the mid season upgrade.