3rd read and first time I've noticed this. I think there's many factors to wilfried's failure but I think the prologue of P4V4 is where his path turns towards failure. I think before this his retainers had highlighted flaws in RM (mainly that she's hard on her retainers, which IMO was BS and purely out of self-interest) but it had never really changed his perspective on RM. But here Sylvester calls her a 'problem child'. IMO Wilfried completely misses why she was called a problem child and lays his retainers feedback and his own biases to define what made her a 'problem child'. Sylvester's wording doesn't help either and he just expects Wilfried to understand.
This is what he thinks:
>Rozemyne was selfish when it came to books and the library—she never showed restraint, nor did she allow her opinion to be swayed.
Translation: She has clear motivation and makes firm decisions. I don't think these are weaknesses. While her motivation might not necessarily the best for an AD to have and can be called selfish, I don't think her attitude or bearing is incorrect. Kind of broadcasts that he will become an easily swayed puppet with no real motivation of his own.
>Furthermore, she was causing major problems during socializing by forming so many bonds with royalty and nobles from the higher-ranking duchies. Things had gotten so bad, in fact, that Sylvester had ordered her to sit out the Interduchy Tournament and the award ceremony.
Again he seems to think the act itself was the problem just cause he found the outcome inconvenient. AFAICT the main problem here wasn't that she socialized to spread trends, the problem was that she ignored all the risks involved and rushed headfirst into it. Going at a much faster pace than anyone expected. Therefore, the duchy isn't ready for the scale of response if this goes any further. The problem on RM's end is that she largely ignores the caution required when dealing with greater duchies and royalty. She makes an apt analogy that ehrenfest are like mednobles but then goes out and shows none of the deference expected, treating and seeing the greater duchies as her equals for the most part. The rest of the issue and the reason she was pulled back was entirely on the duchy not being ready for more. And given RM's unpredictability, there's no saying how much deeper she gets in. This is highlighted in the fact that she deals with more greater duchies in her second year and is allowed to. I don't think she's significantly better at socializing by then cause the core issue still stands (her common sense.) The duchy is just more ready to take on more and she has a better idea of the duchy's capacity as opposed to her instructions in the first year being "Raise our rank as much as possible".
So I think Wilfried just never understood why RM was called a 'problem child', and Sylvester calling her that just knocked her off a pedestal for Willfried. He misidentified her issues and used them as a basis for his own future actions: namely, listen to your retainers opinions more, be very flexible, and don't try to actually do anything. And I think this mindset is what sets him up for the disaster of his retainers and all the other stuff. Had Sylvester not knocked RM off that pedestal in Willfried's mind he might've continued to try to support and emulate her instead of just trying to constantly act as an anchor.
TL:DR: I used to think that Sylvester's main issue with Willfried was just neglect, but I now think that he might've also inadvertently caused Willfried to lose his role model.