I have the Corsair H115i and I did not remove the paste that came with mine and it performs fine. I run a 7700k at 5ghz with 1.34 volts and my load temps are just under 80C. A lot of that will depend on your chip, but if it were me, I would use what it comes with and see how it works, if your temps are not where you want them, then you can get some new paste.
I would buy thermal grizzle kryonaut before I used Artic Silver.