Of course you can't just compare their stats. Joe was used as a winger, Hazard has a free role. Most of Hazard's goals were scored in a single season. Cole played in a superior league, he played a supporting role (which can't be compared to being the star man of a team), he didn't take FKs and PKs, he came off the bench a lot, had to return from injury a lot (lacking match fitness), he's not been the same player for four years due to horrible injuries etc. All kinds of factors to consider. I don't know if you watched Chelsea back then but Cole had a good shot on him and was a pretty good finisher in his prime.