I agree that the spurs cannot find a defender who has the footspeed and length to bother Dirk. I think Horry is too old to play many defensive minutes on Dirk. I used the age points to suggest that this spurs team is older and will not run as well, generally. Devin Brown was a young development project that could play fast and physical on D. Now the spurs have a bunch of old guys(>32 yrs), TP and Manu(knee?). IUt seems like an over emphasis on vets, especially at the three speed positions(PG,SG,SF). They look relatively soft defensively at the PG, 2-guard, and SF positions. Part of this is Bowen aging, Brown gone, van exel over Beno, Finleys minutes, Horry(when he defends a 1, 2, or 3. Maybe Horry has found the fountain of youth, but I see him as a shooter who is a cagey defender with reduced physical skills.
At some point if you cant defend Dirk, you have to make him work and pay for his deficiency on defense. I dont see that matchup being containable for the spurs. Add to this the big speed deficiency at the 1,2,3 (Parker, Ginobli, Finley, Bowen, Vanexel, Horry(part time)) vs (Howard, Terry, Harris, Stackhouse(when well), Marquis Daniels), and you can expect trouble in the matchup. All that being said, TD may be able to carry the load anyway. He is that good.