when you test the click latency of g403, you should keep your g403 on the surface.
If you have to lift G403 off the surface when you test the latency(for example doing a bump test), you should tape a piece of paper underneath G403.
Because G403's debounce filter is not always on. It is only on when it is off the surface. When the mouse is on the surface, there is no debounce latency applied at all. This is the smart design Logitech has on their modern 3366 mice.
If you tape a piece of paper like I said and test again, G403 cannot be beaten.
Get higher speed memory and manage to run your game at 240+FPS with all kinds of v-sync and buffering turned off before you talk about mouse precision.
Memory speed and efficiency is the KEY factor to improve framerates in ALL multiplayer games (eg. OW, WOW, CSGO, LOL, HOTS). CPU frequency or GPU power is NOT.