While the Lakers traded their pick in the 2019 draft to get Anthony Davis, they still did end up getting rookie Talen Horton-Tucker on the roster so that will not change. What we will be covering in this draft is the Anthony Davis trade which is where the Lakers 4th overall pick would be sent.
Using trade machines, a fair trade for both sides consisted of the 4th overall pick, a 2020 unprotected first-round pick and a second round pick, a 2021 unprotected first-round swap and an unprotected second-round pick, a 2022 first-round swap, unprotected 2022 and 2023 unprotected second-round picks, Josh Hart, Kyle Kuzma, Malcolm Brogdon, and Shake Milton in return for Anthony Davis and the previously mentioned pick swaps.
While the Lakers would be giving up a lot of their future drafts in return for this trade, it would send the Pelicans into a rebuild which means they would greatly value these picks. Objectively the Lakers may have given up too much pick wise in this trade, however, their final starting lineup is LeBron James at point guard, Jayson Tatum at shooting guard, Pascal Siakam at small forward, Anthony Davis at power forward, and Mitchell Robinson at center.
This would be a starting five that would attract free agents to take massive pay cuts to stay with the team, along with this, the Lakers would have enough cap space to sign another star player or round their lineup out with veterans for team-friendly deals like they did in reality.
To conclude, if the Lakers were to draft perfectly, they would be in a much better spot than they are today and would likely be locks to win the NBA Finals for years to come and after LeBron James retires, they would still have a young core of Anthony Davis, Jayson Tatum, Pascal Siakam, Mitchell Robinson, and potentially whichever star they signed in 2019 free agency.