I just have never gotten the point of view that its better to draft a 19 year old with potential over a 22 year old with potential. 22 years old isn't old. Players, especially ones taken at the top of the draft that you want to become stars, get better every year. There simply is no age where a player with elite talent stops developing.
Also, its not like a team is going to have a 19 year old on their team all that much longer than a 22 year old. Both the 19 year old and the 22 year old get 4 year rookie contracts. If they are superstars, they both get 5 year extensions. If they are still good they get another contract. BTW, very seldom do players, even the best of players, stay with the same team over 9 years. So saying its advantageous because at the end of 9 years one player is 28 and the other is 31 makes little difference, most likely that player still won't be on the team.
And bringing up examples is ridiculous. There are as many busts of teenagers as there are success stories of 4 year college players becoming great. There are as many examples of 19 year olds becoming stars as 22 year olds that stagnate and never become better in the pros.
Honestly, draft a player based on talent, transferable skills, and how much room you feel that player has to grow. Hield may be the better player than Murray or Brown right now, but he may also have the highest upside even though he has less to go to reach his highest upside whereas both Murray and Brown may not be as good right away but could have lower upsides and may take longer to even reach those lower upsides.
Younger doesn't mean better, it just means younger.