I would suggest we wait until the tour of India before finalising this judgement. Or, maybe even the end of their careers.
I mean, I could ridiculously apply unbalanced logic too... I could say Zaheer had the advantage of having to bowl on dead and lifeless pitches and as such was already versed in those skills....
Essentially, I'd pick Jimmy ahead of Zaheer every time from the last 3 years because I'd get roughly the same standard of swing bowler, with the added benefit of that he's an awesome fielder and can be assed to at least try batting
Give it another 3-5 years, and I may well have just picked Jimmy for his bowling anyway if he carries on maintaining his recent form.