I don't really know what's the problem here with the production. Italeri (before the overall quality deteriorated), Revell and Zvezda always produced cavalry sets that provided an almost perfect fit between horse and rider. So it can't be that difficult. And to force the customer to cut away excess plastic be it flash or whatever to get a satisfactory product isn't exactly a very good idea. Fumbling with a sharp knife or a razor on a 20mm figure get's a little risky with old age and there's a good chance that someone get's hurt - usually the miniature 😜 - so it's not one of my favorite steps in modelling.