Granted that both options increase the flat damage of the weapon, the secondary options both require you to have specific loadouts to get the secondary effect, which I personally feel is a little limiting. Some of us aren't going to use all of the Stalker's kit and some of us aren't going to use melee alone; more importantly, some of use are not going to use either option.
I think keeping the stalker theme requirement is fine, but maybe have a requirement on the other option that doesn't require us to use melee alone? I could argue that 100% combo chance doesn't really need a requirement to activate, but maybe have a sprint speed requirement otherwise, like 1.2 or something similar to other incarnon upgrades.