I didn't have much issue getting swarmed, didn't allow the enemies to bunch up enough to do it. Went through the place sneaking with the finewood bow sniping anything in sight and used the bronze mace to take out any skeles or draugr that got close. Well thinking back there were a couple times were i got unlucky and got a big group on me, first time killed me, second time played ring around the rosie with a tree just walking back to get them in a line so i could turn whack one then go back to circling. Third time managed to get ontop of a big fallen log, nothing could hit me up there.

All in all you want to take it slow, be methodical, and find a safe enough route through that place. By that I mean avoid having to go through large pools of water and maybe setup some wooden floor panels between bits of land that have enough water between to slow you. Also take out mob spawners soon as you see 'em they're often too dangerous there to bother keeping as a farm.