Historical accuracy Vs "vibes"

I'm currently writing an Arthurian short story for a magazine, and instead of the anachronistic post-Norman chivalric version, I decided to go a more historically grounded Welsh/Brythonic route. This means I'm using a lot of terms from Welsh folklore. But non-Welsh readers will not know them, so instead of drawing on well-known tropes, I have to spend a lot of words to introduce the reader into something new.

One example, my protagonist is supposed to represent the female version of a typical Arthurian knight. I used the traditional chivalric title "Dame" for her to communicate that. However, in pre- Norman Britain, knights and dames did not exist yet. And the fitting Welsh alternative, "Bennaeth", would be meaningless to almost anyone.

For now, I decided to just use that title for her, to draw on the readers existing idea of a knight in arthurian lore, but it does feel like I'm compromising on the historical accuracy.

What are your thoughts on balancing accuracy (be it historical, scientific or just some area of expertise) against reader expectations, common tropes and genre conventions? Especially in shorter formats, where explaining something new is costly (in terms of words required).