Drogba performed when it mattered. Ibra never done it in a big game in a knockout stage in Europe. That is why he never won the CL. Drogba at the age of 33 carried Chelsea to a CL that is the difference between being good and being great/legend.
I wonder why this thread is still open. Jovetic's move to Man City should be official some time this week I suspect.
Zlatan is an interesting one. Of course it depends on the transfer fee and wages. No idea what that would be but Ibra would definately make us contenders for the champions league as well.