Very interesting reading, BUT...
I think people have overestimated Harmison's ability to the guise that he overperformed for those 7 Tests in early 2004. Take out those (plus, obviously, Bangladesh and Zimbabwe who Cork never played) and his record is not remotely close to being as good as Cork's.
If you look at Harmison's career at large - ie, outside those 7 Tests - it's followed a very predictable pattern. Regardless of how much of a feelgood factor he's given to the bowlers at the other end, and the batsmen in the team... he just hasn't bowled remotely well, and has never got many wickets other than when the batting has been truly awful (which, unsuprisingly, has happened only on odd occasions). We're talking about 37 Tests, in which he's got decent figures 7 times. That is seriously, seriously poor.
Purely in terms of bowling ability and achievement at the Test level, for me, Cork has bettered. Ask Hussain and Atherton, too, about how much you-want-him-in-your-team factor Cork had, even if he couldn't hit batsmen the odd relatively harmless blow on the helmet like Harmison did with Ponting and Hayden at Lord's 2005.
I don't feel, either, that Cork could have done no better. Had he been left-out in 1996 when the problems first occurred, not been picked for New Zealand in 1997 when things were clearly still not right, and got into the side in 1997 and 1999 when all was well again (he was left-out because of his poor overseas tours of the previous winter) then he'd not have got the disappointing results he did. Injury and the ball-change in 2001 affected him, of course.
And that's before we even get to the summer of 2002, when his handling was about a picture of how not to deal with someone. Every Test he played he probably should not have - and had he not done, he might have had a more successful summer.
Since 2003, though, when he chipped a bone in his ankle before the season and played half-fit throughout, then left seam-friendly Derbyshire for often flatter Old Trafford, he's never been the force he once was.