If I was to play a dead is dead character it would have to be a sneak type character because my Thief/Assassin is never surprised by anything. He always gets the first hit in and can disappear at will when the going gets rough. From my experience a warrior is pretty hard but a mage would present the most challenge due to very low health and little to no armor. I don't think I could do it though because I tend to be too careless and end up dying from something stupid and I'm not about to lose a character for that reason.
Sneaky types definitely have a (much) easier time of it in the early levels, however a warrior or mage type can actually have an easier time of it at higher levels thanks to certain perks. That does depend on opponent and difficulty setting, though, as certain opponents are almost guaranteed death for a melee character on high difficulties unless you have ton of armor and resists.
Melee on Master is definitely rough in the early going, especially if the other guy is wielding a 2H weapon. I use a lot of hit-and-run to string out fights during that time, so that I can pop heal spells between 'rounds' to insure they don't get an auto-kill hit off. I don't use followers, though; someone who does would have an easier time of it, since they, being NPCs themselves, get the buffs that level of difficulty gives.