I refuse to judge managers choices in hindsight like that. (I know I've done similar things, but I try not to.)
I don't think they follow the "playbook" you seem to think all managers follow.
They know a hell of a lot more than we do- not just about baseball and what factors make a good decision or bad decision, and not it's not "did it work or not?" because if that is that is the case, Cora is a genius for turning a team looking like a last place team to a division leader after 100 games, but also how players are feeling, are they ready for a certain amount of pitches, match-ups with the next hitters, who is in the pen and how do they match up.
I'm not saying Cora has never made a mistake. He'd admit he has and may even agree with you on the Eovaldi choice, but I think he's done an extremely great job with this team. I disagree with somethings too, like line-ups and giving players days off at odd times, and in game decisions, but I hardly ever voice game decision decisions, because I know there are too many unknowns for me to pretend to know better.
If Germain was way over is pitch count, then pulling him even before the first hit might have been an even better move. Maybe the wrong move was not pulling him but bringing in the wrong guy.
We'll never know with this call or the Eovaldi call.
BTW, we didn't lose the Eovaldi game because the pitchers Cora brought in pitched poorly. They got the hitters out or got them to hit the ball weakly, except for the one hard 2B. The balls fell in while ours bounced into the stands or off the wall right to the SS. A little luck and we win that game, and no hindsight can prove Cora made the wrong call.
As it ended up, we lost,so it must have been the bad choice. I don't buy that.
I respect the hell out of you Max, but we just don't see this part of game/people judging the same way. I'm not saying I'm right. I was wondering why he pulled Eovaldi so soo, too, but I just will never blame a lost game on a call like that.