Pie, I think this could easily be taken as a confusing subject. I think Reef is saying your skimmer's pumps, (Which are part of the unit) will pull in 3000 litres per hour into the skimmer. (Deltec would have tested this for sure). Its like trying to put a v8 into a mini. It'll work, but you'll get less life out of your chassis and tyres and so on....
It doesnt matter a rats arse if you had seven Iwakis turning over your tank a million times an hour, The skimmer is still pulling in what IT requires for its design. (3000 LPH)
It just means it has more chances to skim the same piece of water than a tank with less TANK flow. (Not to be confused with SKIMMER FLOW).
Get me drift?