So, identical perks on the sword and shield stack, but you can also run 6 unique perks. These two options are necessary for sword dps to dare try to compete.
Empowering Leaping Strike is necessary. You must run it if you want your sword dps to be worth using.
Fortifying Shield Rush will keep you alive, and it’ll also slow enemies if you fully-upgrade it, and swords at 200str and a few rows down the leadership tree both give +10% damage to slowed enemies.
You’ll want a slash damage + leeching ring. +refreshing if you can find/afford the 3 perker.
I recommend keen/bane, vicious, keenly empowered, bane, rogue/enchanted refreshing move.
You can stack bane on both sword and shield. It does stack. You can test on fort dummies.
Keenly Empowered + Slash = 20% empower. Heavy attack once every 5 seconds = 30% empower. There’s your empower cap. You don’t rely on Oblivion, but it’s nice for when keenly empowered isn’t active, as you will be at empower cap whether you have keenly empowered up or are in an oblivion.
Whirling blade isn’t necessary or worth it, and you probably have a spear in your group, anyway. I recommend reverse stab as it lowers cooldowns and the more you get to use empowering leaping strike, the better. Contagious Reverse Stab will make the ability deal at least 10% more damage.
I recommend Leaping Strike, Reverse Stab, Shield Rush.
I run 266 strength, 200 dex, 50 int, and 5 con in light armor as SnS/VG dps (or tank.)
At 200 dex, you deal 10% more backstab damage.
At 50 int, you deal 10% more crit damage.
Dropping 45 points from your primary attribute for 50 int is a loss of 5% base damage, but an increase of 8% for a +3% damage gain. Because of this, being in a position to backstab is important.
5 con light is the only way for a sword dps to compete, but we can compete. Stack full refreshing for the maximum carnage.