Trae is without question a next-level bad defender. And despite Ja not doing much there (as you note), there is a gulf between Trae and well, basically, everyone. We really can't continue to treat all "bad defenders" the same. There is a continuum, just like good and bad offensive players.I'm not so certain that Ja belongs above Trae. He's got the physical tools to be a better defender but he's certainly not using them (yet). Add in potential injury concerns with Ja and it wouldn't shock me if a year from now their order is flipped. Very curious to see how he looks alongside Murray.
That said, Trae is a better offensive player by a decent amount too. At least right now.
If I were buying stocks, I would buy Ja and sell high on Trae. Ja is still on an upswing, and there is a reason to believe that he has another leap in him. Trae is who he is, which is currently still a slightly better player than Ja. Trae still has some incremental growth built in, so I wouldn't say that it's a given that Ja ends up the better player in the end. But that's where I'd put my money.