If studies show that endurance training increases shortening velocities of slow-twitch fibers, if you had no natural speed, could your absolute speed get faster by just doing really intense aerobic work? And could your maximal aerobic speed actually get faster than your anaerobic speed?
Like studies on elite Kenyan runners who can go 13:00 and faster sat some have 75-90%+ plus slow-twitch fibers and basically no leg strength in comparison to controls, but can run sub-16 seconds/100m for the whole 5000m.