Why should it matter if Serena is playing like 02-03? What makes you think that Serena is going to be affected by Kim now? Kim hasn't played in a long time we don't even know if she is going to be in top form. I don't see Kim doing much damage to Serena anywhere outside of maybe clay.
It matters since you are basing Kim's chances vs Serena based on how she did vs her in 2002-2003. Serena is not even close to the same player she was in 2002-2003 due to fitness, commitment, weight, and who knows what other issues. Thus if Kim could return to her 2003-2005 form, which is not a certainty of course, she would do much better vs Serena than she did then. Much lesser players than Kim like Kuznetsova and Azarenka are playing Serena in slam matches they really should have beaten her recently, so why on earth wouldnt Kim have a great shot now if she returned to her former form.
Also Kim was only really in her prime 3 of those matches. Basically her prime started at the year end Championships in 2002. In those 3 matches she beat Serena easily in the year end Championships final. Totally should have beaten her in the Australian Open semis and had one of the most colassal chokes of all time. Then Serena's turn to have an easy win in Miami. So based on that prime Kim was not an easy opponent for even the vastly superior to today prime and fit Serena, once Kim reached her prime. That perspective is skewed by so many 2002-earlier matches in their head to head when Kim wasnt the same player yet as 2003-2005 either.
True point, but no offense to Justine in top form against Venus in top form I am giving Venus the edge on hardcourts and grass. I don't think Henin would have regulary beat up on Venus on hardcourts and she would not have been able to do damage on grass. Venus has a lot of talent.
Sorry but from 2004-2007 Justine would have won almost any match between her and Venus except on grass. Justine has simply been the better player ever since the start of 2004 onwards at the very least. The 2007 U.S Open was probably the best non grass court tennis Venus has played since the 2003 Australian Open and it still wasnt enough to even get a set off of Justine. If you are talking about prime Venus vs prime Justine than that might well be different, but Venus's prime has been long over awhile now. Maybe you are referring to your guess if they were in their hypothetical primes together, in which case I could believe your perspective. Otherwise no.
Would you like some examples of when they potentially would have met? The Olympics in 2004 Venus was slated to meet Henin in the quarters but couldnt even get a set off an out of shape past her prime (except for last hurrah 2005 year) Pierce who herself then was easily beaten by Justine next round. Would Venus have ever won that match? Then Australian Open 2006 they were slated to meet in the 4th round. Venus lost to some player I cant even remember the name of, and Justine waltzed to the semis, and gutted her way past Sharapova to the final. Again what reason is there to think Venus would have ever had a shot if they played here. All the examples I can think of when they were in the same part of the draw Venus couldnt even reach Justine since she lost to a much easier opponent than Justine.
I bet if Serena had barely played Justine that whole time too you would also have assumed Serena would have regularly beaten her outside of clay still. However when Justine and Serena played pretty often again in 2007 it was proven that was far from the case, and Serena is better than Venus anywhere except grass as well. Justine from 2004-2007 won over twice as much as anybody else including the sisters, she was by far the best player in the world overall combining those four years.