Colin Kaepernick and Russell Wilson proved during the NFC Championship Game mobility is a good trait to have in a quarterback that scouts should look for. Wilson has also shown us it is OK to be short. If you think Johnny Manziel would be bad in the NFL because he is short and mobile, you must really hate Wilson, who will go to SB 48. Now do you think Manziel would be bad in the NFL?
Scouts should consider mobility in a QB, it should not be a make or break trait in my opinion. Wilson and Brees are 2 good qb's in the NFL (Brees is great) but other than those 2 who are some other short QB's? I can think of more tall good qb's than short good ones. Wilson and Brees are the exception to the rule...not the norm in my opinion.
As for Manziel...no one knows. It's all a quessing game. Manziel will be as good as he strives to be.