Why does MCH have a robot?

[AvenoMatt]

I like to think that even though the MCH is a physical job, and I think this for every job, they use magic. Now not a lot of magic like casters and healers but but some magic. I mean this already kinda makes sense since the MCH's bullets are made of aether with the use of the aethertranformer on are waist. I just assume that it also allows us to materialize or manipulate technology too. The bioblaster, drill cannon and auto-crossbow are just are gun being rearranged into those other weapons. Maybe the aethertransformer is also a pack were we keep spare parts and when we summon rook we manipulate those parts into it and same with queen.

[Berethos]

I like to think that even though the MCH is a physical job, and I think this for every job, they use magic. Now not a lot of magic like casters and healers but but some magic. I mean this already kinda makes sense since the MCH's bullets are made of aether with the use of the aethertranformer on are waist. I just assume that it also allows us to materialize or manipulate technology too. The bioblaster, drill cannon and auto-crossbow are just are gun being rearranged into those other weapons. Maybe the aethertransformer is also a pack were we keep spare parts and when we summon rook we manipulate those parts into it and same with queen.

In the sense that "magic" is manipulating aether, every job does use it, whether it's to create a spell or to imbue an attack with some extra oomph or boom.

Incidentally (ShB spoilers)

it's why Thancred has to have his Gunbreaker bullets infused, as he can't do it himself, being unable to manipulate aether. If you bring him and Mini-filia along in a trust dungeon, he'll occasionally call out for the cartridges from her and will then follow up with attacks that use the charged cartridges.