Salaries were reduced overall, not just for big men. The BBs could mess around with the salary calculations and balance them between positions, but it would be a lot of work and mostly just serve the purpose of royally screwing up the finances of teams that train Guards and suddenly give teams that train big men a huge boost. If balanced perfectly, your weekly team salary would be exactly the same (what the BBs want it to be this season)
Given that balancing the salaries between big men and guards better would just cause massive issues to training teams and not actually change anything in the economics of things, why would this be a problem?