Hi, i used a free afternoon to create a table for the World Cups 1982-1994, the four world cups, that had 24 teams playing in two different formats. Spain 1982 had a 2nd round with 4 groups of 3 after the top two teams qualified from the 1st round. The other 3 world cups had a round of 16 implemented after the 1st round with an additional number of 4 3rd placed teams reaching this second round. So, I wondered, how the schedule would have looked liked, if these formats would have been interchanged within these 4 editions. the green format shows what really happend and the red format shows, what could have been. From 1982 we would have had both finalists already meeting in the QF. 1986 would have granted us the first Germany v Brazil encounter at a world cup. At 1990, the later finalist Argentina would have been out after the 1st round. The same would have happened with Italy in 1994.
What this makes clear for me is that 1982 (already one of the best World Cups of all time) would have been far better if they had adopted the 16-team knockout round by then. It would have taken longer for FIFA to come around to simultaneous kickoffs, but eventually an Algeria-esque situation would have occurred in a 32-team World Cup to force the change.