The amount of damage you do is proportional to the amount of stamina you have. So even though you'll do the power attack animation with low stamina, you're really only slowing yourself down.
This.
If you are a warrior with dual wield, you place 80% of your levels into stamina, and 20% into hp.
Any warrior build with low stamina is a gimp build if its damage you want.
But can I make a suggestion?:
Dont play dual wield at all.
Why?: Its too powerful once you get higher up. Its just not fun. You will do around twice as much damage or even three times, as a 2h wielder.
if you do go dual wield, stay clear of enchants and smithing and alchemy, at all costs. Or you will be rerolling in 30+ hours from now when you are tired of one shotting giants and the lower dragons.
To the person saying power attack is to break guard: This is NOT oblivian. Power attacks in this game does damage.
First, Power attacks do a TON of damage on its own. Now, just for dual wield, you have perks that increase Power attack damage by 100%.
You are literally doing around 5+ times damage with a power attack compared to a normal attack. If not more.