Remember that saddle position is set relative to your crank position. It is not used to compensate for a short top tube. You can use a longer stem and some spacers to move the handlebar up and forward but very long stems can feel awkward when steering at lower speeds.

I started out with a 19.5" (50 cm) frame on a used bike that a salesman told me was "close enough". Setback seat post maxed out of the seat tube, seat set back on the rails, stem all the way up (old style quill stem) and a couple of changes of handlebars and eventually I got it to be what seemed fairly comfortable. Then I learned more about bike fit and got some advice from someone who knew bike fitting. Turned out that I needed a 21" or 22" (54-56 cm) frame depending on geometry. New bike of the proper size, saddle mid-rail on a neutral seat post, stem actually 1 cm shorter than stock with a slight rise and the bike fits me perfectly. It is far more comfortable and handles much better. Yes proper fit does make a difference over work-arounds for a too small frame.