Power helps but it's not the end all be all when it comes to getting a KO. Speed is very helpful in getting a KO as well and timing too. Look at George Foreman, Manny Pacquiao, Floyd Mayweather, Muhammad Ali, Mike Tyson....all those guys could KO pretty much anyone Foreman was pure power; Ali, Pac, & Floyd have speed and timing; Mike Tyson hand great handspeed and power.

I think it's easier to try and KO someone if you're open to all options. There's more than one way to skin a cat.