I’ve also been casually looking at girths. The issue I’m having/seeing is the anatomical or shaped girths have huge leather ends beyond the buckles. Some girths I’ve emailed vendors about have 4 inches on each side!! Even if you get a 20 inch girth the entire girth ends up being 28 inches long!
My saddle has long billets and I’m trying to find a shorter girth that doesn’t end up at or over the bottom of the saddle pad. It’s strangely harder than I’d thought!