Complex sentence: No one can dispute that, in particular, the signing of Walker and several other Heisman Trophy winners gave the league much-needed credibility, but the Dixon plan did not call for as much spending on talent as the league did in 1983.
Split into simpler sentences: No one can dispute that, in particular, the signing of Walker and several other Heisman Trophy winners gave the league much-needed credibility. However, the Dixon plan did not call for as much spending on talent as the league did in 1983.