The Ps(S) would be base factor 2
and as it is the Blades bound it (the Ps) would get a extra +1 for "any of its front edge upslope of all its opponents"
Given it a final factor before rolling the dice of 3
Not sure how you get the extra 1 from your example.
Grading does not come into play until after you have rolled the dice and compare totals.
So this combat is Blade 4 Ps 3
lets assume the Bd roll 1
the Ps roll 2
its now Bd 5 Ps 5
Now grading
The Bd are I and take a -1 for I troops
equal or less
They (Bd) also take a -1 for the Ps being (S) and their opponents being (S) have scored
equal or more
So combat finishes after grading Bd 5-1-1 =3 Ps 5
The Bd recoil
Regards
David Mather