Oh a flat back can have topline all right. Diddly has a lovely topline now.
;Normally a horses back is mildy you shaped. As in the tiniest sway to it. However a horse with a flat back has a completely straight back, with no you bend in it. It gives the horse great strength in the back, but as I'm sure some of you know, (see the amount of saddles I tried for reference) it is SO difficult to fit saddles to a horse with a back like this and you need to be really careful. Apart from that, and not looking quite perfect when stripped, a flat, straight back tends to be more of an asset than a hindrance. So I've found anyway.