I think, if your fuel systems pretty clean anyway, then one filter between tank and pump should get anything (mine does does not appear to get dirty, though I change it every few years, as plastic and may start disintergrating). This is a step up from from factory spec, which I think was normally adequate anyway.
Never had problems with crap, getting into carbs myself with this set up, though car is in regular use, so prob helps to stop rust/crud building up in pipes etc.
Extra filters could be making the pump work harder?.
Dave