The odds are against basically any pitcher breaking into the league, of any size, to have sustained success mostly injury free as a starting pitcher.
You have done nothing to show that Stroman faces taller odds because of his shorter stature. Nothing scientific, nothing logical, not even in a common sense sense.
Would you even give half a mind to the notion that the only reason to ignore pitchers *slightly taller than Stroman would be to fit your narrative? There would be no discernible functional difference between the heights of Stroman and, say, Eddie Cicotte, or Pedro, or whoever (in terms of effect on their health or whatever).