As the article states, Sherman was terrible at both the draft and free agency. TT is great at drafting, decent at free agency. Wold was pretty good at drafting and pretty good at free agency. While some of us clamor for the big FA, I think that TT knows it's one of his weaknesses and just stays out of the game to focus on drafting.
It's also important to note the Wolf was outstanding at picking up the street free agents during the season when a hole was identified in the O-line or elsewhere. TT hasn't matched that success yet, but also rarely breaks the FA $$ piggybank.