I’m not sure I buy your Baseball Savant argument. It’s not like Nunez started playing yesterday. We’ve seen him perform for parts of three seasons. His style of hitting (somewhat low BA and OBP, fairly high K rate, good power) has some value. The average team had a .227/.312/.407 OPS at DH last year. Nunez has hit .253/.319/.463 for us the last three years, and better than that last year. So he is a good enough hitter to help some team primarily at DH.
Hays and Santander could be better hitters but they aren’t now and if you want to assume that those guys will get better, Nunez could as well.
Sure, Stewart benefits but he also could get at bats regardless if Nunez is here. I can’t imagine Mancini is an everyday player right off the bat.
You are wrong. Just go look at the 2019 DH stats for example..several teams in the AL had the same guy taking up a large majority of the at bats, with many of them getting 500+ at bats and that doesn’t include Alvarez, who the Astros brought up later in the season and was their exclusive DH for the rest of the year (he had just under 400 at bats).