Definitely makes sense, since a brace of flintlocks compared to an assault rifle is a pretty massive difference. I personally don't think Ruby violates the whole no gun rule if its treated like that, but that is just my personal opinion really.
I'll actually go grab a Master slot so we can have an even number, in case we want to start things off sooner rather than later, if that's fine. Does Ezreal work?
I had some other ideas. Caster Alexstrasza. Archer Sylvanas. Assassin Xayah. The list goes on and on honestly. I think that's the core fun of a crossover RP for Fate is taking all these characters and fitting them into Servant classes.