National reputation: I agree - I'm playing in the Welsh Premier and Caernarfon have hired a Spanish manager. He may turn out to be rubbish, but most if not all Welsh club managers tend to come from Wales or are English, Scots, etc, living in Wales.
Lower level football being easier: I've played or managed with a half-decent bunch of players and with a bunch of absolute ***** pub-heads. It was much harder to manage the pub-heads... The better the players, the better they understand tactical instructions and the worse the players the less likely they are to listen to any manager, let alone a crap one like me.
As for the managers around you being less able... says who? Isn't it just as likely that, as far as your players are concerned, the other managers are probably a lot more able than you?
It's down to you (real life or in-game) to prove to them that you do know what you're talking about and then maybe they'll start actually listening to your instructions.
There is also the team-gelling factor to take into account. Other managers will have had more time to work with their players whereas you need to build up your rapport and team-spirit. I like the fact that SI
seem to be taking this into account and, initially at least, this would explain why my team seem so utterly crap...