Never really thought of that equality rule where Mon, Abet, Manny and Yoyoy were not allowed to play for one team was a sh1tty one. I actually thought it was consistent of what the PBA espoused back then - parity among all teams. It all started when Crispa disbanded and then Deputy Commissioner Tommy Manotoc (Commissioner Naning Yenko was a mere figurehead) spread out the players to different teams instead of making them form a dynasty team with Shell, the company that bought the Crispa franchise. Thereafter, he instituted the PBA draft where the least performing team of the previous season would get the top pick in the draft. Since Shell was a new team and only got Cezar, Fabiosa and Cristobal from Crispa, Manotoc gave them the first overall pick which turned out to be Sonny Cabatu. This allowed the Azodrin Bugbusters to enter the Finals in the All Filipino of their maiden season, losing out to Great Taste.
Then, of course, the big men parity rule. Considering that Fernandez and Guidaben were practically dominant then (winning the 1982 to 1984 and 1986 MVP plums), Manotoc spread out these two along with Victorino and Villamin to different teams in 1987 to allow every PBA team to have a chance of winning. True enough, from 1986 to 1991, seven franchises won championships in an 18-conference span. And yes, this also led to the PBA becoming the biggest sports entertainment spectacle in the country, attracting fans and viewers all over in what can be described as the PBA's glory years.