Matic does seem to work pretty hard though, and there's not really any excuse for the others barring Ibra due to his age.
I think it's a fairly simple. If we want to get away with working less hard than all of our opponents, it has to be down to one of two things, either a) we have a game plan based around this that actually works, or b) we're so much better than everyone else that we win every game with something to spare anyway.
The later is out the window straight away as we're distant second in the table to a team who work harder than us. The former doesn't really apply as our game plan often seems to suffer due to our static play. On Saturday for example we were unable to apply pressure in the way we should have been, or control the game against a team with inferior quality footballers, because our players don't seem to be able to press or close space up as a unit. They're reluctant to cover the ground as a team to do it, so Brighton always managed to play the ball up the pitch. When we get the lead our players then are reluctant to cover the ground to close out the space again, so we end up under needless pressure on the edge of our own box, hoofing the ball to no one. All of this was basically down to us just not working hard enough. If it's a tactic, what IS the benefit of it?
We don't have a team filled with poor athletes as you seem to suggest. If we do it's because they are not fit enough. Even if it's not because of that we need to look at the fact it is giving teams we play an advantage...and the fact that City are currently easily ahead of us and we need to look at areas we can improve....because at the moment nothing I see in our performances suggests we're capable of catching them.
Games where we are rolling teams over 4-0 aren't the problem. Games like Saturday or against Chelsea though, are still happening far too frequently. If it was just games like Chelsea away you could understand to a degree...but we shouldn't be looking like the lesser side against the likes of Brighton, Southampton, Huddersfield, etc. just because they decide to put a shift in and get themselves organised.