Ok so I have a question regarding Servant Stats in correlation to their Mana rankings.
In a fanfic I was writing for Fate, I had a really weak Master and gave her Archer (EMIYA) With his original B ranking Mana reduced to D because I thought that is how stats work; The worse the Master, the less potential they can bring out of the Servant they have (of course the Master can't make the Servant go over their limits (and yes I know Servants have a limit to how much the Master can help them).
But then someone brought up to me that isn't how stats work, so I took a look at Saber and her Altar version and her different stats in Mana from Shirou to Rin to Sakura, and it went from B, to A, to A++.
Now I want to know just exactly how the stats for the Mana thing work so I don't go screwing over the Nasuverse while I am writing my fic. I know my post sounds all sorts of weird and I am sorry I can not make it anymore clearer, but I am always happy to answer a question detailing what I mean and if this is the wrong board to post this question in, I am sorry about that too.
Thank you for any help you can give me in this matter.