I think most fans would argue the opposite. When Favre used a 343 variant he deployed two of Witsel/Dahoud/Bellingham/Delaney/Can in front of them, as RWB he only trusted Meunier, whose profile is much more defensive than Morey's. The peak of that was the game against Cologne where he not only used two defensive midfielders, he also used two wingbacks who offer nothing going forward. Effectively playing with 6 defensive players and 4 attackers against a team parking the bus. Dortmund hold the record for the most clean sheets this season. Favre's problem wasn't that he couldn't get the defense under control, it was that there were lots of games where they were barely able to produce a single clean chance, especially when Guerreiro was missing. At the start Haaland made up for that with a beyond world class conversion rate, but once he got wasteful/injured and Dortmund's finishing turned ordinary they basically dropped points every time someone scored a goal against them (e.g. Lazio home, Frankfurt, Cologne).