Difference being that McFadden and Pearson actually feature for their clubs (have heard Pearson mentioned before when he was out of favour elsewhere, never McFadden), Porter has had problems establishing himself at Derby mainly due to injury.
For what it's worth, I agree, probably a load of rubbish, but I can see the logic in the rumour. Brown has contacts at Derby, Porter knows Motherwell, needs a run of games, Motherwell need a striker. Of course, this is a case of 2+2+2=3167, but it's not the most ridiculous suggestion I've heard this summer. The Alan McCormack one is always a belter...