Two things. Firstly, where do you think that instinct comes from? It comes from the training pitch, going through the same routines again and again and again til you do it without thinking. You practice in groups til you know the runs of your colleagues so well that you do it automatically. Its like playing a musical instrument. You look at the score and your hands move without you investing your full consciousness. Its something you learn, and re-learn, something you can get better or worse at. The decisions they make are heavily influenced by the way the manager trains them all week. They don't just to go to the training pitch to get fit.
The other thing, that kind of work is on the rapid, instinctive decisions that players make in the moment, whether to release a through ball or keep it, for example. They still play within a broad framework set by the manager. The positions a manager asks them to play on the pitch determines what passes they can make or receive, which in turn determines how you attack the opposition, and defend from their attacks. If the boss asks you to play wide, and you wander off to the middle, you're in trouble. Indeed SAF's famous tea cup incident came after Strachan refused to stick to the wing after being told to play there in a European game.
Watch City 0-1 Chelsea from a few weeks ago and tell me that wasn't tactics at its finest, determined by the coach and executed with skill by the players. Of course they have license to try things. Once you're counter attacking for instance you may just go with the flow, move into space where it emerges, shoot when the time is right. But deciding whether to counter attack quickly all game or hold the ball and push out slowly; deciding whether to attack by crossing from the wings or playing through balls through the middle; deciding whether to push or be patient; the manager determines all of those, by the players he picks, the training he does and the instructions he gives them before and during the game.
The very best football comes when a specific game plan is put in place by the manager that suits the strengths and weaknesses of the squad and the opposition, and gives the players license to work flexibly in the parameters of that plan in a way that suits their strengths.
Looking at United this year, Moyes keeps making the same decisions, which aren't working. His central midfielders always sit deep, spending more than half their time in their own half, even at home. That's fine, depending on how else you play on the pitch. But if you then try and stretch the game in the opposition half, and ask RvP to spend all his time right up top, you end up with huge gaps between our own players. That makes passes more and more likely to get picked off by the opposition. That in turn frustrates the players, who then try riskier and riskier things (like Rooney) that don't come off, or just play it safe every time (Cleverley, Young) and frustrate the fans.
Of course that's not the whole story for the season. There wasn't a single reason I had toast for breakfast, so there certainly isn't a single reason for the complex and drastic decline of a multi-million pound club comprising 25+ highly tuned and trained human beings. But when a team is performing badly, you have to find a way to play that they're comfy with and that suits their strengths.
