sherwan_88 and Janj thanks for the suggestion. spectra I politely disagree with your opinion becuase I had a landrover defender 80 with Visco fan, I never had problems of stucking up of the fan even in 1 meter deep wadding on rocky terrain. I'm a Pakistani but live in Catalunya province of Spain where stratum is similar with our Potohar region. However, our seasonal channels have rocky beds and sometimes soil & sand (silt?).
I'm retrofitting an old Stery Pinzgauer 710K with VW 2.0 TDi diesel engine along with matching ZF 6 speed transmission. The engine manufacturer recommends both options i.e. Electric or Visco fan for radiator cooling. In that scenario I sought recommendations on this forum.