They are essentially replacing two players with this move:

1. McDonald at DE supplants Ulbrich at the TED, and
2. J.Smith at OLB/DE replaces TBC/Haralson/etc.

Both upgrades, imo. McDonald is a better fit at 4-3 DE than Ulbrich is at TED (both Ulbrich and Thomas are better as weakside 4-3 OLBs), and J.Smith is simply a better overall player than either TBC or Haralson.

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