Best lore-friendly suggestion for Ashe if I've given Knight to Basch?
I don't think it matters too much... Just because she was using a sword and shield in the sewers, it could be just that's all she was able to scavenge. Doesn't necessarily mean she's a full on knight per se.
And in the original vision of XII, Matsuno envisioned everyone being able to learn all Licenses anyhow. So the new 2 Jobs limit, I sort of envision that as a rule for this story: let's have everyone focus on 2 Jobs or roles each for the purpose of this specific quest -- not that it's a hard lore rule (that if she takes Uhlan that she is only an Ulan forever). I think the Ivalice lore establishes Licenses as being pretty free in general so I don't think it's break lore or canon to think, 'for pre-XII, she was using KNI Licenses, then for the XII story she was using BSH Licenses, but for the RK story, she switches to TBM Licenses.'
That said, the Licenses that she does have a history of preferring are basically KNI (XII) (she uses 1H swords in scenes and then the 2H Licenses would fit the story swords she gets), and then TBM in RK. TBM also gets Durandal (but no shield), so something like RDM/TBM would fit her pretty well (1H sword form TBM at endgame + Shield from RDM, plus healing and buffing). KNI/TBM, too.
Vaan is pretty clearly shows preference for KNI over SHI though, too. He starts with a dagger, but in all the XII, RK, and Dissidia art, he's using 1H swords (and usually pieces of plate armor not leather). (KNI works well on 2 characters though.)
Then you can make Basch a BSH instead since that's his RK Job, and BSH still kinda fits his story well. BSH/MNK I think works well... You could envision that he became spiritual
. MNK probably fits Basch or Ashe the best, I guess... not in the sense of MNK Licenses, but the MNK lore I think are the sort of warrior-pilgrims at Mt. Bur Omisace, and that sort of
path fits Ashe and Basch I guess.
But again, I think the nature of Jobs just being Licenses they decided to divide up for
this story means you have a lot of freedom. It doesn't mean Ashe is an Uhlan, through and through. Just means she's using those Licenses for this story. Licenses, in the lore sense, are kinda as changeable and temporary as equipment. I think, at least. It's fun to discuss either way. I still go back and forth on my lore
fit, too, and my own sort of headcanon hhhh.