The 5 ball category is very large,you can draft the phenomenon,as the good player,as sometimes also some very bad player(I drafted a 5 ball 5 potentail rating G with all respectable except for atrocious in OD).
You drafted the phenomenon this time,but if you drafted "only" the good player or worse,you would lose an entire season of training than a 18yo with good but not exceptional skills
The value of a season of training is not low....
If the 7k 19yo draftee will became the rule and not the exception,I will consider to draft the 19yold...