As there is every season, there is going to be some debate on this thread probably on whether 5/4 A+ 18 is better than 5/5 A+ 19 or not. I personally would set your players up like this:
1) 5/4 C A+ 18 (This is the clear top choice. A+ 18 year old at 7'0" means he might actually have some secondaries and he could turn into a very nice big for you, while also staying closer in your salary range considering he has 4 potential rather than 5.)
2) 5/5 C 6'9 A+ 19 (This is where there will be debate. Some people may tell you to put this guy first, which I wouldn't suggest, or 3rd, or even 4th. I have him second, because a 5/5 is very hard to pass up on. My only worry with him is that he is only 6'9" but is listed as a C rather than a PF so his secondaries are probably weaker, than they should be at 6'9". Still, he would be a great trainee for you as a 2nd trainee, or a first trainee if you do not care about getting players on the U21 NT.)
3) 5/4 PF 6'8 A 18 (I know that the other 18 year old is A+, but assuming that you can get two of your top three picks, you are going to want to try to get guys who train together easier, and 6'8" is much easier to train along with 7'0", rather than a 6'2" SF)
4) 5/4 SF 6'2 A+ 18
5) 5/3 PF 6'7 A+ 18
6) 5/3 PF 6'4 A 18
Assuming that you get two of your top three options, you should end up with two bigs who you can train to be core pieces on your team. Best case scenario in my opinion are if you get the 18 year old 7'0", and the 19 year old A+ player with 5 potential.
Anyways, this is my opinion, and others will probably disagree with me a little bit, but this setup makes the most sense to me and would probably be the best case scenario for you.
Murray/Harris/MPJ/Grant/Jokic - 2020 NBA Champs