It's not an assumption. General play has improved in all areas, hence positioning has improved. The evidence is in the ability of teams to execute the plan more often and the fact that most teams now play similarly on a regular basis, yes some better than others but in the main, the standard has improved all around. Teams have way more technical ability throughout the squad now than they did 20 years ago, the baseline has improved massively ergo attacking, defending, etc has improved.
I can only put that down to coaching, fitness and analysis generally being better than it was 20 years ago. Like I said, humans aren't robots so it's noticeable when they get more robotic, it means they've been drilling it into them repeatedly in a more targeted way.
Don't agree with your assumptions at all. Ten hagg said that with the current players he has he can not play like he did at Ajax. Because technically they aren't that good. If anything I think the opposite of you, technically players are worse now. It's more about being athletic.
Just compare our team from 2008 to now. Technically no comparison. I can't think of one player that is technically better in our current squad then anyone from 2008. We even used to have a segment called trick box on the man und web site. Haven't had that for a while now.
General play has improved? How so? Would 2009 Barcelona not destroy all teams out there right now? Even the current man city team?
Defending has improved? Our currant defense is brutal to watch. Do you not remeber how solid defensively we used to be. Our back line of Rio, vidic, and evra with who ever at rb was one of the best defenses I've ever seen.
Imagine a team today with Rooney, Ronaldo, and tevez as our Frontline. Technically far superior to anything we have right now.
A midfield of Scholes, Keane, and Carrick.
A backline of Neville, Ferdinand, vidic, and evra,
And in goal van Der Sar.
Our 2008 team was miles ahead in attacking, defending, general game play, passing, and technically superior to our current team.
If anything analytics have made the game worse. Where the players can't think what to do if something doesn't work so they recycle the ball. Because they don't know how to think for themselves. If anything general play is worse now then it's been for a long time.