A significant problem for Shafer was injuries at QB(Hunt) , and lack of any back-up QB who had played at this level. The issue was talent, and recruiting, at the most important position in college football. Not to say it wasn't also offensive schemes, but the main issue was not having a capable, healthy QB who had a chance to learn the schemes.
When people talk about Babers' schemes, and assistant coaches, they usually mean the offensive side, where the principal coaches have been together for four years. His defensive coaches weren't geniuses in 2014, when BGSU had a young defense. He had to bring in a new DC in Brian Ward in 2015 to replace his long time assistant Kim McCloud. His DL coach is new this season. His DB coach has only two years of overlap with Babers. There isn't a lot of P5 experience among the D-side coaches. Are they real good with their defensive schemes -- maybe, but how would anyone know?