I think it's OK to say. Sportscasters openly talk about athletes' ages and recognize there is an age window for top performance. Right now Ken is 45 and Brad is 41, which isn't a lot older than James at 35.
Because I'm a nerd, I looked up the ages (when they won) of the last 6 TOC champs: Roger Craig, Colby Burnett, Ben Ingram, Alex Jacob, Buzzy Cohen, and James Holzhauer. They ranged from 30 to 35. James was the oldest. This doesn't rule out someone older or younger winning, but it's good evidence of an optimal age range for being a peak Jeopardy player.