2) Perry Minasian
Billy Eppler is undoubtedly one of, if not the worst GM the Angels have had in their team history. He failed to build a winner, but he did, at the very least, sign Ohtani. Additionally, he didn't have Ohtani at his absolute best.
Minasian replaced Eppler ahead of the 2021 season. The 2021 season just so happened to be Shohei Ohtani's first MVP year. Ohtani was then the AL MVP runner-up in 2022, and won it in 2023. Three straight dominant seasons from Ohtani and nothing to show for it. The Angels never won more than 77 games.
Injuries hurt the Angels in a big way in each season, mainly to co-star Mike Trout, but Minasian never built a roster capable of winning around Shohei. That simply cannot be disputed.
The Angels went all in this past season, trading prospects and even going over the luxury tax at one point only to finish with the same record as 2022. 73-89. No, Minasian does not deserve blame for not trading Ohtani. There's no way Arte Moreno would've given him the green light to do so. He does deserve blame for the players he acquired.
The entire 2023 trade deadline will go down as one of, if not the worst in baseball history. The Angels traded away their best prospects for players who did not produce and were instantly gone. Just an absolute disaster. Minasian has done some things well, but his failures around Ohtani is what he will be remembered for.