Which race can dual-wield Swords the easiest?
Solution 1:
The only thing that makes dual-wielding easier (or harder!) is the One-Handed skill (or lack thereof!).
Redguards start with the highest one-handed skill, but this initial advantage isn't anything that other races can't overcome with a little bit of effort.
Solution 2:
You might be looking for orc. Orc's berserk ability to take half damage and do double damage for 1 minute will let you mow down hard targets before they can get you.