Correct me if I'm wrong but I kind of think this one single hire was what influence you to post what you first previously stated. In regards to John Harbaugh I think he shown growth as a coach..Younger Harbaugh wasn't into analytics, hiring coaches from college , hiring former NFL players as coaches and etc. I think it's misguided belief that he stayed the same for 18 years . Doyle is 29 years old and honestly it's probably not common for teams to have coordinators that are 29 years old . From the top of my head I can only think of a few coaches that were coordinators around that age which was Sean Mcvay, Josh McDaniels, and someone else but I forgot his name but anyway I don't think Harbaugh never had interest in younger coordinators. Truthfully Cam Cameron was 46 years old when he was the ravens offensive coordinator ( beginning of Joe Flacco Era)and Greg Roman was 46 years old as well when he was hired as the ravens offensive coordinators( beginning of Lamar Jackson era). I guess these ages are considered old but seems like fans believe Harbaugh was hiring a bunch 60 year old offensive coordinators. the oldest offensive coordinator John Harbaugh has ever hired was Marc Trestman I think he was about 59 at the time.
Overall in regards in to Declan Doyle he's consider a exciting hire due to his age and who his mentors were but he's probably the most mysterious hire ever because I don't think any one can even pin point what his offensive system is and what his philosophy will be . The excitement for him is basically pure on hope and the idea that the ravens hired a young coach just sounds so nice. Outside of that we really don't know what to expect or what to see but I guess mystery of that is what makes it exciting. Until proven other wise its probably fair to say Cam Cameron, Marc Trestman, Gary Kubiak, Greg Roman, Marty Mornhinweg , Jim Caldwell and more recently Todd Monken are better play callers than Declan Doyle. If anyone does not agree that then that's crazy cause none of us have ever seen this guy call plays before but that's some high optimism.