I thought I'd be that boring stats guy who brings stats into a discussion because maybe that's what we need instead of blaming each other for not watching the NFL...
I looked at 3 games from the NFL (not a big sample, I know, but it's a start), counted how many times the #1 WR lined up on either side of the formation, so here are some numbers.
First I went all the way back to 2013 and Denver@San Diego, simply because some people might want to argue that Sanders is the #1 guy in Denver, so 2013 was before Sanders arrived. I only looked at the first half where D.Thomas lined up on the Left a total of 7 times and on the right a total of 9 times.
I then went to the 2014 matchup in London between the Lions and Falcons. Here you could make the argument that either J.Jones or R.White was the #1 WR for the Falcons, so I took notes on both. Here there were enough plays in the 1st quarter alone and I didn't want to focus on a single team too much, so this is only the 1st quarter numbers.
J.Jones: Left side - 7 times, Right side - 12 times
R.White: Left side - 8 times, Rights side - 11 times
3rd and final game I looked at was Denver@Detroit last season (week 3) because I wanted to look at Sanders/Thomas where you can argue that either is #1, and Calvin Johnson who is clearly the #1. Additionally I didn't count any plays where the WR (Sanders, Thomas or Johnson) lined up in the slot, a bunch formation or tight to a TE. I only counted the plays where they were split out wide on the sideline. I counted all plays in the 1st half of this game.
D.Thomas: Left side - 9 times, Right side - 8 times
E.Sanders: Left side - 10 times, Right side - 10 times
C.Johnson: Left side - 9 times, Right side - 10 times.
On Detroit's last drive of the half I also noticed that Aqib Talib played man-to-man coverage against C.Johnson on 10 consecutive plays.
Observations:
First of all, even with a small sample size, I think it's safe to say that the #1 WR is moved around a lot - I even saw both Sanders and Thomas in the slot a bunch of times. I think they're moved around so much that it kind of feels meaningless to argue over which side he should ALWAYS line up at.
Secondly, and I think this is MUCH more important; I think we need a way to assign a CB to a specific WR. This isn't always the case - some teams play a certain CB on the same side of the field at all times, independent of the WR - but if I'm the coach, I want my best CB on my opponents #1 WR. It doesn't matter where the WR line up, I want my CB to follow him around everywhere, just like Talib did on 10 consecutive plays, on both sides of the formation, against C.Johnson.
If EA 'fixes' this issue and have the CB or #1 WR line up on only one side of the field all the time, I don't really see that as a fix. It would be much better if we could choose who our CB's should mark throughout the game.
As I said, small sample size but hopefully interesting at least.