I am so curious how this is going to play, I think you are right and onto things. If I would have had the time to put in the play time, I probably would have drove myself nuts how they were. I think I am going to fire it up on my lunch break and see what happens. I have mine on 8 minute half and Legendary, here goes the first trial after while and see what comes. I also believe you are right on the Marking and Line Length.
EDIT:
I just took a break from work and played a quick match before lunch so I could tell where if any thing I need to adjust. Played as Sporting KC vs. Colorado Rapids. Ended up with a 0-0 match. Plays much different / better than I have ever had. I think the biggest things that were a change that I had to get use to was the fact that the play is more fluid and it's more strategy playing into shots and set up.
I definitely played like a new born noob though. WOW, what a change that made. Plus I just got FIFA 21 and hadn't set some of the settings that I like (I usually play End to End with Pro camera. So the broadcast for some reason threw me off. I played hand held and automatically the first thing I noticed was the fact that the graphics look quite a bit different both in movement and clarity, which from what I knew was not supposed to be changed in any way. But I am not blind, head to head with 20, there is a difference.
Overall happy with the marking and line, to me it seems more fluid but more realistic as far as the way the spacing works, it was a good mix of getting a good turn in play or getting burned.
More to come!