Did they though? They were not spectacular successes, but they also were not much money in the greater scheme of things. Kingery is not good value of course (0.5 WAR) for $24 million. We would have given him 3 minimum salary years and then released him (but then signed someone else to play the utility role). So that is $20 million wasted.
Herrera was $31 million. Even with the suspensions and poor late performance though we actually got some value there. The contract covered 2017-2021 We actually got 4.5 WAR in those years ($6.88 million per WAR) even though he was useful in only 2 of those years (2017 and 2021).
Total investment $55 million for 5 WAR. So probably a little expensive but not outlandish.
The main point is that many of these long term contracts for younger players that lock up a year or two of free agency work out spectacularly well for the team giving the contract. Assuming we pay Nola the $16 million option for him next season we will have invested $56.75 million in his early contract. We are at 13 WAR so far and it is reasonable that we end up at like 18 WAR.
The Phillies need to do more of this. The Nationals biggest problem is owners that don't do any of this (lucky for the Phillies). Their owners respond to fan pressure (resign Strasburg because he just won us a World Series) rather than signing guys like Harper and Turner and Soto and Rendon to below market contracts when they had the opportunity. It would have cost them $300 million to get Soto after the World Series, but it was worth it because the price is $500 million now and he is gone.
Who knows if Stott would accept, but it would be malpractice for the Phillies to not think about doing this sort of contract. I think he could be more valuable than Harris for instance because he is a middle infielder, but also less expensive because he does not have loud stats or tools at the moment. Maybe he'll bet on himself like Dansby Swanson seems to be doing, but a 24-year-old taking $70 million guaranteed in a sport where things could fall apart fast like with Kingery is nothing to sneeze at.