I'm fine with that if you have less health. You guys should be the definition of a glass canon in this game. Fast with high dmg but punished if you ever get caught out/surprised.

It seems like you guys have this scenario in your heads of like a take 10 paces turn and shoot kind of deal when you describe the dmg.

I think it's way too early to try and modify the damage output before the faction's even released to Founder Access.

Most weapons Wound most targets on a roll of 6 anyways. Granted, their ability to actually Wound targets their Strength normally would not allow them to does give them an edge over a Bolter against such targets. That being said, you need to settle down and decide if you think Shuriken weapons should be more powerful, less power or, the most sensible idea, asymmetrically balanced with other weapons because of the Bladestorm function.

Bladestorm and Rending have the exact same chance to occur, if you roll a 6 TO WOUND. Of course, in the TT, you have a chance not only To Hit but also To Wound your target, where as in a real-time scenario like EC you deal a certain amount of damage to your target if you hit them with a shot. Some things in the TT cannot be translated directly, such as the Bladestorm and Rending rules that are best translated as guaranteed Armor Penetration.

16.7% pen to Armor will still function and be viable as every single unit should have Armor, including those with the Mark of Nurgle. The Mark of Nurgle should not remove Armor it should increase Toughness that increases max HP, reduces DMG dealt to HP, increases out-of-combat HP regen and enables healing from Nurgle-based psychic powers, while also reducing the Marine's move speed. The best way to implement it is guaranteed Armor Penetration.