When you are in a dangerous province, and you see a lvl20 player, are you feeling bad when you attack them? That's your choice.
You could say the same thing about me attacking someone that is 6 levels higher but has no mercs (and I have 5). I don't feel bad, I want their gold and if they aren't strong enough to win.....
Perhaps you should try that. You may not be a higher level player, but you can have excellent mercs and great equipment on them. If your mercs are strong enough, you may be able to beat those lvl 29 players.