AAA performances are far more meaningful for players in their early to mid-20s, after a few years in AAA ball, hitters learn how to "play" junk ball pitchers (who lack command or they'd be in the Show) and younger pitchers. When he fails to translate that kind of production to the majors, it's obvious he has major flaws which ML pitchers know how to exploit.
I'm skeptical of Clemons as well, WRC+ 104, 121, 129 in AAA.
Dahl is a better bet, ML WRC+ 113, 111, 111 then fell apart due to injury, so if he's healthy, you can at least make a case he might rebound.
Luplow is also 30, but he's had the most recent ML level performance in 2021, WRC+ 117, followed by 79 and last year marred by injuries.