Ben also deserves some blame (IMO) for not recognizing where to play players. If he really thought Ihnen could play the 2, why wouldn't he have thought Battle should play the 3?
I do agree with you, the biggest issue is the roster construction that forced these horrible lineups. However, I am not convinced Ben realized how poorly constructed the team was until he saw them play. That's a failure in analysis and construction - while those things obviously overlap (you construct based on your analysis), they also are independent issues.