Yes the free agent tsunami had an impact on all, but not remotely evenly. Teams that had sold off lots of their players and had money were given a massive advantage. Teams that spent on players in season 11 or 12 were at a huge advantage with those players sometimes worth 20% of what they paid for them. The teams in the same leagues that just sat still in those seasons and saved or spent on their arena had a massive advantage. Many would argue that this was the direct cause of one of our ABBL winners being able to win the championship. If that isn't significant then I don't know what it.
it was a process where good managers could act
They can act on any process, however this one turned the whole BB econony upside down. It brutally punished anyone that was training bigs. It made all training of only moderate value. It really sucked the profits out of the lower leagues. Where everyone used to compete with $20,000 players and make a healthy profit, now anyone can afford multiple $60,000 players, and they do, but they aren't making any money and their teams are heading no-where.