Doctor MJ wrote:... I think it's pretty clear at this point that pace & space would have been the optimal approach in any post-goaltending basketball world, but in practice offensive and defensive effectiveness might have swung back and forth....
I don't think pace and space is the optimal approach in any world in which the 3 point shot is not more effective than dumping it into the post player. In 70s NBA for example, with no 3 pointer, I think teams that build around spamming long twos are going to be extremely inefficient offensive teams, ie. losers. There will be some benefits in terms of opening up driving lanes but modern pace and space relies on forcing defenses to come out and cover those long shots because modern players hit the 3 at a rate which produces more efficient scoring than the league's ability to score using even post play, much less midrange jumpers. If the long shots the sort of inefficient shots that defenses invite you to take while hanging back to cut off the driving lanes and you still only hit them at a 35-40% pace while the other team is averaging 45% plus from their post or double post offense (while drawing more fouls too), pace and space is suboptimal.
Even in the early days of the 3 point shot, pace and space doesn't work with a league that shoots .285 from 3 (1968 ABA), or .280 from 3 (1980 NBA). You have to get the league average up to around .333 or higher which is post 1995 pretty much (to account for the extra foul draw from shooting in a more crowded environment) for it to start being an effective strategy and that may be overstating how early it can come on line because until the mid 2010s, it was still mainly guards and wings shooting the 3's while big men worked inside.
Now, if you are saying that every era of basketball uses modern rules and that coaching down to the elementary school level were emphasizing the 3 point shot the way they do today so that players come up to the pros as effective 3 point shooters, then sure. But that's not reality.
To tie this back to the OP, it then seems intuitive (though I don't have numbers) that the more important this difference between outside shooting efficiency and inside shooting efficiency is, the more impact a great rim protector like a Russell can have relative to a great offensive engine. So, while I would expect that in today's game, where the rules and refereeing favor offense and teams spam highly efficient 3 point shooting to set up the rest of their game, a great offensive player might be able to have more impact than a similarly great defensive player but in an era where interior scoring was king, a great interior defender would probably have more impact than a similarly great offensive player.