We actually don't know what qualification for "Voyager" class are. Heck, we don't even know its actual class name as it was named like that just because of the only known one, Voyager. I mean we have theories that may be more correct than others but still

Foreigner

Rider because of the TARDIS, feels kinda boring as an answer though

Foreigner because the guy comes from outside the Earth

Alter Ego because of all his different lives, though that's a bit of weird justification since they're all still him (kinda)

Pretender for the same reason as Alter Ego

Caster because of the gadgets n shit, boring answer imo but it is there

Archer. Everyone qualifies for fucking archer bruh. Throw a rock and now you're an archer.

Imo Foreigner is the best fit but Alter Ego and Pretender could make for the most interesting storylines in a crossover.

Actually the doctor would qualify for each standard class

Bro has done it all though an pretty sure he would also be Savior and forgnier

Saver is kinda complicated class

Though most likely he would be rider if he was summon like one of the guys above said thanks to the tardis and it would one of his noble phantasm along with the sonic screwdriver

Though I thank he does deserve it the doctor has saved humanity many times though alya might be salty because he ain't human

I don't think saving humanity qualifies somebody for the class. I don't remember buddha saving humanity

Caster probably

Traveler, which is what Aoko Aozaki would be