Can't pretend it can be easy managing England but it is a completely non comparable scenario, the reasons you've mentioned are just part of the reason why.
There's nowhere to hide if you have a bad result or can't get on with one or two of the players. The next game is always a few days away and your squad is the same one you see every day.
You need a tactical plan and a long term coaching strategy, not just to pick from a country full of players who have all been coached by the likes of Pep for you.
You need to be able to defend and pick up your players, not just underhand slag them off to the media and pick someone else for the next tournament.
You don't end up with two thirds of your fixtures being hand me outs against the likes of Malta or Albania. 90% of games you will be found out by the opposition instead of 10%.
The media won't give you a break or put positive spins on things to help get behind the team. They will actively want you to fail, relentlessly.
It'd be an unmitigated disaster. There's the morbid part of me that would almost be entertained if it did happen just because of how ugly it could get.