Groenkloof1

So this big guy was sitting on the Wattbike next to me in the gym and looking very impressive as he was pumping those "Rugby prop" legs. I peeked at his screen and did the same hart rate as him- then looked at his Watts/ KG only to see it was 1,7. Now Mr Skinny here next to him was doing 3,1 Watts/ Kg. Now I know why "rugby props" play rugby and do not ride the TDF

Question: Two riders with the same FTP, say 4 W/ Kg but one weighs 100kg and the other say 66kg. Who is going to be stronger on a hilly course? Even though the theory says they have the same FTP- will the lighter rider not still be the better climber?