EDmuch...just saw your question, thanks for asking. I would request that a few of the people on this site please chime in as my offer might be a bit light but let me be clear. Hader is going to cost a lot and it will be painful, especially for those of us who grew up on this site in the mid 90's when all we had to enjoy was the draft, pharm system and the dreams that accompany those two mechanisms for building a team for the future.
That said, I simply believe that DD has been around long enough and talked to enough long time Phillie insiders to recognize that the Phils have usually tried to "catch lightning in a bottle" with many of their reliever choices and it has rarely worked out. I suspect he does not want to repeat this mistake and instead would prefer to go for a home run, and Hader looks to me to be the only home run out there.
Look, Hader helps this team in so many ways. He immediately becomes the lock down closer that Neris et all could never be. I think DD has heard from enough people that for too long every 9th inning lead was a "hold your breath, please Lord help us get through this" and more times than we care to think about, said closer would fail and a seeming victory became a crushing defeat. They say that nothing is more demoralizing to a team that blowing a 9th inning lead and I believe its true. It just stays with you. I think with Hader around it does 3 things.
One, it gives the starters more confidence that if they can give the team 6-7 good innings, their chances of winning are solid. Two, it defines the roles of pitchers like Alvarado, Neris and whoever else is in the Phillie pen. Neris, in particular, seems well equipped for the 8th inning role, Alvarado the 7th. Seems like a potential monster trio to me...lefty power pitcher Alvarado in the 7th, the righty Neris in the 8th and the overpowering lefty Hader in the 9th. I think with Hader in 2021 the Phils win 5-7 more games than they did. 5-7 more wins puts them on the cusp of overtaking the Braves...and we all know where the Braves now sit on the MLB totem pole. Three, it just gives the Phils such a mental lift. They immediately have arguably the best closer in baseball, and a guy who has successfully pitched 3 days in a row. Theoretically, he could be available to successfully save all 3 games of a 3 game series against the Braves or Dodgers. This matters.
As for the cost, it will be painful. O'Hoppe, especially after his wonderful Arizona stint, will be one of the players, Rojas likely another. Brewers will want a couple of young pitchers back, perhaps guys like Miller and Brognon might fit that bill. Brewers would likely want 1 more youngster back...though not Stotts, Painter or Abel.
One more thing. I am of the belief that certain players are just so disruptive in the clubhouse that they harm a team regardless of how talented they perform on the field. The have sure had a few. Dick Stuart, Danny Tartabull and Jonathan Papelbon come to mind. I put Jean Segura in that category. I would try and get the Brewers take Segura and in return take on Jackie Bradley's onerous contract.
I know Segura is still a good hitter and certainly has his moments. But his history tells me that his attitude is detrimental to the team concept and moving him would be addition by subtraction. Just my opinion, others may disagree. I will say this much. Andrew McCutchen was a beloved Phillie and I have no doubt that Segura's lackadaisical approach caused McCutchen's unfortunate injury, one that he and the Phils never truly overcame.
So there you go, ED. I am sure that a few of my names wouldn't be included, I feel very confident that a few would, This is a deal that DD is famous for making, a splash that instantly makes the Phils a more dangerous and appealing team.