You have lots of bullets in this game, so aliens must be penetrable to them. Knives are the same type of damage as a bullet: metal objects delivering a lot of energy over a small surface area.
The only human guns with bullets are the Rifle and Chaingun...
Reminds me of the knife from shin seiki evangelion series (It's a vibrating knife that "can cut through anything like butter" although that last statement is obviously false)
Do use this for dueling friend grangers. It's not fair any other way.
Turrets have bullets too. Turrets are not handled but, yes, we can say there is lot of bullets ! :)
But there is a big difference between a bullet fired and a knife, the first is the power, the second is we often do not use the knife to stab but also to cut (a throat, in war games).
In reality, instantaneous bursts of energy (bullets) are just as effective.
In video games, such as unvanquished, they deal as little as 5 damage.
In games such as SSBB, bullets can do as little as 3% damage, while a single punch can deal 32%.