People like to hype up offensive minds, but Belichick, Pete Carroll, Mike Zimmer, Dan Quinn, and Ron Riveria are among the better coaches in the league, and are all defensive guys who have done pretty well. I'd say Sean McDermott is pretty good too considering what he's working with.
And there's plenty of offensive minds that have ended up as utter failures as head coaches. Hell, Hue Jackson was once that big, hotshot offensive mind that everyone wanted.
bill bellicheck has the greatest qb of all time who basically runs his own offence + BB is the best coach of all time
The Vikings are very much thriving on good OCs but notice that they'll likely end up with their 3rd OC in 3 years because Pat Shurmur just got a HC job, and John DeFilippo is gonna get one at the end of this season too... Mike Zimmer's a great coach but he's reliant on a good offensive mind - do you think the vikings succeed with case keenum without an offensive mind?
The Falcons are a mess on defence which is what Dan Quinn should be a specialist at solving, and their offence is reliant on great playcalling and OC - they lost Kyle Shanahan and it's taken almost 2 years for Sarkesian to show anything as an OC - and the Falcons are 3-6
Ron Rivera is a great coach but the Panthers are a much better team because of what Norv Turner has done with their offence this year
you are right that these guys are great coaches - but outside of bellicheck who has josh mcdaniel, they all have to hit the offensive coordinator carousel every year (or 2) and hope their team stays functional because the grim reality is that if you dont have an offence, your team means nothing in the 2018 nfl
The Patriots arent winning games because of their defence, the seahawks are certainly not winning games with their defence anymore, the vikings arent winning games with their defence (although they are the only team of the bunch who could claim they might be able to), the falcons are 3-6 and not winning games, the panthers arent winning games because of their defence even if it is good, the bills are only winning games when their offence fires
doesnt matter how good those coaches are - its an offensive league and good offences beat great defences in this current format
if you want a consistent offence (and that's something you should want in this period of the nfl) then you need to invest in an offensive minded head coach or you'll be constantly changing your organisation
of the above teams you've mentioned the head coaches of:
mcdaniels has been rumoured to maybe be given a 2nd chance on the HC carousel
Brian schottenheimer has taken over the seahawks offence and has done well - they probably get to keep him for another year
John DeFilippo is gonna be an HC somewhere
Falcons probably get to keep sarkesian mostly because no one will want him
Norv Turner probably stays at the panthers coz he's been around the league a long time but maybe he gets another shot at being a HC
beyond that the Titans just got a new offence and OC under their defensive HC - they're gonna lose Matt LaFleur probably after only 1 year
matt patricia just got to Detroit, he may end up losing Jim Bob Cooter if enough teams are looking for offensive help as HC
the list continues...
