This is a straw man argument. Nobody's arguing over pixels of difference. Everybody's looking for realism up to a point, without sacrificing fun. It's just that they're more willing to put the effort in to find that point than you.
They're arguing about the principle of how the game positions players, how a tactic works versus what it's trying to represent in real life, how the game flows as the ball is won or lost. It's not just fancy shit that we have no business getting involved in, and it's not a needless embellishment which doesn't really change anything - it's the difference between having two or three defenders when a team counters. It's not pedantry to point that out.
For the record I think it's fine that the DM is joining the CBs - it's Konami trying to represent a specific tactic in a way that produces more team individuality, and it might not work for every team but it's cool and unique that they're including stuff like this and the false fullbacks. Over time I'm sure Konami will add more advanced tactics, maybe making this specific thing about a DM dropping back into a more generic attacking option just like asking CBs to go up for free kicks.
It's not pedantry to identify that the CPU automatically switches from ATK-DEF level 4 to 2 the millisecond it loses the ball, thereby stopping the attackers from maintaining pressure up the pitch. It's something which would make significant improvements to the game without costing anything more than the time it takes to code in a 3-5 second timer and do a quick bit of QA to ensure that it works.
Also, just because there's a variety of opinions doesn't mean that it's futile trying to find the best way to do things. There's a very easy solution to that problem, which is to (a) understand that all opinions are not equal, and (b) that people's observations are more important than the conclusions they draw from them.
I get that some people don't really want to participate in discussions like this, or feel like it's all a bit over their head, or that they can't make a distinction between enjoying a game and seeing the need for improvement in certain areas. Some people have more analytical mindsets than others - sometimes to a fault, where they try to spot patterns without enough data or enough isolation of the variable they're trying to test for. Some people are happy to leave things mysterious and not ever really know.
But it's a primitive argument to say that the choice is either (a) to enjoy the game or (b) to work out what it's doing. They're not mutually exclusive, and it's anti-intellectualist rubbish to suggest that there's no place for (b) or that it doesn't actually yield any benefits when some people stand out from the crowd and put the effort in to explain where improvements should be made.
I have no issues with the PS4 version of the game, in fact I'm gutted I had to leave my PS4 at the summerhouse so can't try the demo, its the PC version and the way Konami treat the PC platform I have a problem with which wouldn't be relevant here anyway 
Had a chance to play the game more and I can confidently say I'm not going to regret my preorder. I'm actually very excited about the release now 