I thought about that, but I decided to do it over who was the absolute best bowler in the world over a period of two or three years or so, as that is what Steyn has been so far thus it would provide a better analysis regarding the initial question of the thread. I mean for me who the best fast bowler was over the 80s is pretty much a wash between Hadlee, Imran and Marshall, but in the interests of precision I broke it down into who was exactly the best at what time. Obviously Marshall was superb in the early 80s too, it's just that at that particular time Imran and then Hadlee were just a little bit better, then later in the decade vice versa.
I also disagree with you that Snow is clearly better than Steyn. Obviously we will have to wait until the end of the latter's career to make a full judgement, but considering his career to date I would take Steyn ahead of Snow every time.
It's funny, Snow is someone who very often seems to slip under the radar. He always used to do with me until fairly recently, when I've done a bit of reading around and examined the facts closer. Snow looks, on first glance, like a merely very good bowler. Yet on closer inspection he was capable of being, and for a decent while was, one of the best you'll see. Snow played Tests for longer than he should have and missed a good few Tests he should have played in the prime of his careerHe was, in the latter respect, similar to Fred Trueman (ie, that he missed them because he was perceived to be a rebel of sorts), but Trueman was so good he was still better than almost anyone by the very end of his Test career. Snow also needed motivation, and sometimes did not have this. The reason he tends to rate so highly with fellow seam-bowlers of the time and just after is that when he slipped himself into top gear, he was dynamite. Unfortunately, there were times when he didn't.
As I say, I feel Steyn's success of the past 2 years does not prove him to be on track to be one of the best there's ever been, and I reckon he'll finish his career merely as akin to someone like Waqar Younis (indeed, I think his best hope is to do so) - a bowler who just attacked and attacked and had no other approach, meaning that when his attacking weapons weren't available (as inevitably happens to almost all bowlers sometimes) and on the occasions he was having an off day (as happens to absolutely all bowlers sometimes) he'd sometimes be quite horrible, but when they were (and when he was on song) he'd be truly devastating.
Waqar Younis, however, finished-up a merely excellent bowler - one who had phases of magnificence and phases of ineffectiveness. Snow, had he had more luck with selectorial whims and had someone found a way to keep him motivated more often, might just be in the very top category of all. I've said it 100 times, I don't believe Steyn can ever be that, though there's precious little question he will be in the second tier unless something goes very severely wrong.