If you mount the shocks further in they will apear to be SOFTER as the lever action from the suspension arm is increased and the distance the shock travels over a specific bump is lessend.

You may also find the RPM arms are not helping as they are a lot more bendy than the standard ones, you might be seeing flex from them and asuming its the shocks.

I didnt like what they did to the handling so i have gone back to the standard arms, i keep a stock of spares, but the newer ones are stronger anyway and i havent broken any for a while.

I run mine with 1 red and 1 blue at each corner, 4mm preload, on the innermost mounting hole on the arm (lets the chassis bottom from big jumps and saves blowing shocks) and stock oil and pistons and its great over most surfaces.