I am 4'11" and have a 27" inseam.
Riding a horse that is large across where the saddle goes makes my short thighs stick out and hard to let my legs hang down properly, not stick out forward in a chair seat.
I prefer to ride horses that are narrow across, feel like I am riding a fat hippo with the thicker built horses.
I guess that if you are tall and long leggity, you can adjust easier to more horses.
Then, the pelvic shape of women tends to be a bit wider and permit them to straddle a thicker horse easier than a man would, other considerations being equal.
I don't remember just now which books have been touching on all this.
Maybe someone else can guide you to those?
There are correlations but they are in essence two different things, the tree and the seat.
The tree fits the horse (the tracing is used to determine the tree). So you got tree that is different width, or different slope, among others variables.
The seat fits the rider. Its construction should comform to the rider's anatomy (such as how rapid a rise it should have, how wide the twist should be, where to place stirrup bar, etc, among others).
A saddle is a fusion of these two, with tree at the bottom for the horse comfort, and the seat on the top for the rider comfort.
A very wide horse, hence very wide tree, often force wider seat than a narrow horse may require, but, it is like saying all stock prices should rise and fall in sync with Dow Jones (after all, Dow Jones is the average of the major stocks), when in reality, even though they interact with each other, you will some stocks can move in opposite of Dow Jones.