I'm not an expert on the subject of Helfrich, but I will give you a few insights that might help. Helfrich is a local family, for many years I would finish my fly fishing trips at "Helfrich boat landing", the most respected local fly fishing guide service is run by the Helfrich family. I've used them for fly fishing trips in Idaho (Salmon River). I play duplicate bridge against one of the Helfrich's.
Second, Oregon got in the habit of hiring small school coaches to run the Oregon program and they were quite successful with this strategy. Mike Bellotti, Chip Kelly and Helfrich all came to Oregon from small schools and were hired originally as offensive coordinators. The concept worked well for Oregon. Much better than hiring a head coach from a big program and having him come in try and change everything to "His way" then flop after 3 years.
Oregon became well known for promoting from within the coaching staff and for having very low coaching turnover.
I guess the net result is perhaps the coaching "gene pool" became diluted and it caught up with Oregon. Taggart fits the small school concept, but he comes from a much different coaching "family tree". So we'll see how it goes........
Oh, and we may have another "Marcus Mariotta" type guy at QB. Plus we do have another "Mariotta" on the team, Marcus' younger brother is at Oregon