Rooney is twice the player Drogba is. Drogba is just your typical goal scorer, he doesn't go back to tackle or win the ball and just stands in the box waiting for the ball, Rooney has much more strength than him, better vision, a better shot and overall a better footballing brain.
Did you not see the chelsea game at the weekend? Drogba was back in his first third of the pitch picking up the ball and pinging passes all over the shop iirc he set up 3/4 of the goals as well as scoring! i was always in the opinion that centre forwards should be scoring goals, i wasnt aware that was a problem lol, how many games now has rooney been goalless 13 or is it 14 now? :p