Guys like Jordan, Pippen, and Kobe had similar body types and games to Brown and Tatum, and they did not have chronic knee or calf issues. Kobe had some issues when he got old, but he was good throughout all of his prime years. Those guys also played a lot of minutes.
You can't blame it on Stevens or overuse or on Jaylen's game. Sometimes this stuff happens. I don't imagine it will be a chronic issue.
I think some of the mentality today has gone overboard on load management across the league, and on the idea that somehow guys are so much more athletic that they injure themselves more. You can't tell me guys today are more athletic than Jordan, Pippen and Kobe. Lebron who's extremely athletic also never gets injured.
Now Smart, his type of game is what gets you inured often. Avery Bradley had to stop playing that way early on after he got paid in order to extend his career.