I think the ceiling for Lonzo Ball is a high level role player.
I do not the see the creative ability necessary to be a player you can build around. Either as a scorer or as a passer. Lonzo is creative in transition and moves the ball well in the halfcourt but he doesn't create enough in the halfcourt because he cannot get enough dribble penetration. So he doesn't pull defenses out of position well enough to frequently generate scoring opportunities for teammates. And obviously he cannot score. He is terrified of being fouled and having to shoot FTs. He has no midrange game. His perimeter game is dodgy too. It is not a good mix.
Ball defends well and rebounds well but he doesn't contribute enough offensively to be a guy you can build around.
I don't think anyone has said Ball is a #1 option type player. He is very much in the Rondo mold of a player. Of course Brown isn't that type of player either as his overall game just isn't good enough to be on that level.
Historical Draft - Portland Trailblazers
PG - Magic Johnson, Tony Parker
SG - Clyde Drexler, Dennis Johnson, Alvin Robertson
SF - James Worthy, Alex English
PF - Charles Barkley, Ben Wallace
C - Moses Malone, George Mikan, Brad Daugherty