I don't blame Capers for players missing tackles and blowing assignments. But I do think his philosophy clashes with Thompson's, because Capers' scheme seemingly requires veteran understanding of a system, but Thompson perennially provides one of the the league's youngest teams.
When did the marriage work best? When veterans like Cullen Jenkins, Nick Collins and Charles Woodson balanced out the younger guys. It's not Capers' fault those guys haven't been replaced in both experience and talent. Right now the veteran leadership on defense is a bit thin, especially when their top talent (Matthews) has missed 9 regular season games the last two years.