This thread is useless w/o pictures. At least in my case I cant say if you are right or not over the bike w/o seeing you.

You can hold better maybe with the short stems but if you lack of flexibilty then is clear that a short stem will work better. Now if you are like 6 feet and you are using a 8 cm stem then is clear that something is wrong just because the numbers do not match with the usual stuff unless, you are like a t-rex or you like to ride like in a MTB position, but w/o seeing you is really hard dude...

ps: 56 frame and 8 cm stem do not match, unless you are riding a bike that is too big for you, just in case.