Good observation, rachy. I think you were also on to something about there being an element of the wearer’s inherent style, or panache even. For me I think the quality and fit of items also helps non- quite- matching, and also garment SHAPES that don’t look so disparate together even when colors are not- quite matching. I think that overlaps with texture—so a soft knit pullover or a cardigan is more forgiving both because of “ relaxed” style and texture.
I would typically be a big wearer of gray for” bridging”, but I’ve also noticed that rich brown colors work well with navies and blacks because is sometimes more unexpected and because browns might be available in “ luxe” leathers or fabrics. So top & pants in same-but-not-same neutral, with a great brown leather belt.