the first reason is cabling and second reason is due to here(iran) we have high amount of parazit so we need to install one dish in proper location that we have low amount parazit so the reason is these.Im sorry
BUT again
what do you want to get with it ?
You can not use both LNBs at the same time because you have DiSEqC between.
I do not understand the function of the second fixed LNB
when they are connected with one cable from DiSEqC.
i know i cant use 2 LNB in same time