Those trades helped the Nats down the stretch and in the playoffs but didn't really have that much to do with them turning their season around. They lost Turner early (and had also lost their RF from the year before) and just took a while to find their groove. Their strength was still starting pitching and offense, and they were already in the wild card position on August 1. Of course, so were the Phillies.
Also funny that Rosenthal was one of the Nats' problems last year.
In this weird season the Phillies also have a good offense and pretty good starting pitching. These moves could help. One more move could definitely help. Getting the guys we are missing back might too. Heck, if a legit #3 starting pitcher was available that would be good too.
Their reluctance to bust the tax this year kind of tells you how worried they are that they might have to bust it next year. JT, another starting pitcher, one or two relievers, and then what if you want to keep Didi or have to upgrade one of the other positions? Without moving either Cutch or Segura hard to free up another penny.