I certainly would have preferred one more arm. The lesson of last year shouldn't have been don't ever spend $ on veteran relievers; it should have been, have a diversified portfolio. Because they all get hurt. But there's nothing about Morgan, Seranthony or Arano that makes them higher risk than if we'd signed a purportedly healthy guy, or someone whose last injury was a few years ago.
I think Nicasio's inability to get a deal tells you how teams are valuing relievers this year as well. His 2018 was so bad (FIP or no FIP) that teams are probably wary too.
In the end, they chose to spend on Wheeler and Didi instead of relievers after spending quite a bit on relievers the past two seasons, and that seems wise to me. The mid-tier guys in free agency weren't anything special and I would not have wanted the top guys. If Pivetta or Velasquez can be like Brett Myers or Madson (who was even more definitely a failed starter than) that's the key. It can also be addressed in July.
A team with a bad bullpen won the World Series last year. We don't have quite their rotation obviously but I don't think this team is any danger of falling out of the race before the deadline. As much as the bullpen injuries were devastating last year it's not the reason they got cooked in June, losing Cutch and having a bad starting rotation was.