I have to disagree with his take. "improve..pool of position players." Why is July the time for this? July is usually the time to sell established players for prospects which he did. A low grade for the return may be justified. I don't know what kind of players were available.
To improve the position players makes much more sense during the offseason. Holding onto talent now may facilitate a trade in the winter of major leaguer for major leaguer. That's not usually the case in July.
Once the free agent market starts, there's usually some guys pushed out their roster and at that time we may be happy to have a Jiminez or Soto to package for a hitter.