@RooboMochi
well, get fucked, thats how adaptation works, they always cut content from the source material, wheter is important or not, in this case, it was very important, and is not something that happen only in this arc, oh nonononono, they have been doing this since season 1, but thats not the case, when it comes to adaptations, this discussion always can come, you like it or not, specially since arc 4 was over years before season 2 was even announced.
setting that aside, i think youre forgetting something, the witch of envy was the last witch to "die" or well in her case, she was sealed, and she was sealed waaaaaaaaaaay after echidna died, so she cant give any substantial response other that just theories without any real base, again, this is something that is cut from the web novel, and AGAIN, this was a very important bit of information to understand everything, but whatever, subaru doesnt even meet echidna here, he meet echidna a few hours after the carriage arrives at the sanctuary, but AGAIN, its an adaptation problem, kinda like with the netflix's "the witcher" show, but that show makes things even worst than in re zero's case, i can understand why they cut the part where wilhem mentions that there can be an answer for rem's problem in the playades watchtower (location where arc 6 is currently happening and about to end), i can understand why they changed the situation when suabru meets echidna, but for fuck sak|e, why did they cut half of all the conversations between subaru and echidna, not just this one, the other one that happens in the first trial too, the events of the second trial are also cut, when daphne uses her power on subaru is also cut, the mention of how the only humans that were able to be near the witches without getting crazy besides subaru were Reid astrea (the first saint sword) and flugel (the sage) was also cut, the demonstration of satella and the witch of envy being two separated individuals fighting for the control of the body is also cut, and that stupid subplot of the teleporting necklace came out of nowhere XD, that thing was just for garfield to recognize that subaru and company work with rosswald and thats just the first ones i can think of about all the chapters that adapted the first cour of season 2, and you may say "well, they can add it in the directors cut version just like in season 1" they wont, they didnt include all the IMPORTANT content of season 1 in the directors cut and they definitely wont add none what i said before in season 2's directors cut.
Im not defending subaru, he is written to be really a braindead moron sometimes, but this time was not one of those, because just like you said, subaru actually chills and thinks about the things that happen before, i mean, be ready to see 2000000000 IQ subaru in season 2 part 2, or maybe not, maybe they will make more unnnecesary changes making him look like an idioteven more than he actually is, but im glad you didnt read the web novel in this arc, beacuse jesus christ, the things that he says to otto out of jealousy about emilia made me want to otto to punch subaru right in the face, so yeah, that beat up that otto gives to subaru to clear his mind was one of the most satisfying scene in this arc and im not tlaking about the punch he gave to subaru in episode 13. but thats it, trust me, this history is written waay better than most peolpe think it is