I have 68" Longbows, 62', and 60" recurves, and also a 54" solid "Farbenglass" Herters recurve #65, that stacks like crazy. To be honest, I see no difference in length of the bow. I'm 6'2" and pull 30" at my anchor point. Long bow, short bow, it matters little, as I seem to miss with them all on an equal basis! Seriously though, if I pick one and spend a few days shooting just that one bow, no matter the length, everything seems to work better. I think practice and just shooting ONE bow with good arrows is the answer for me.
Remember as a kid, with either a bow, slingshot or an airgun, how deadly you became over the course of a summer, just shooting that ONE weapon, day after day?