After a turbulent yet successful first year of starting from Haren and Blanton I wanted to look at their stats vs. Hudson and Mulder's. I'll throw in Zito and Harden's numbers for fun. Here's the minor league totals according to thebaseballcube.com and the ages are their first season with 10+ starts.

Old Aces   era   h9    hr9    w9    k9     whip    ip     age

Hudson     3.55  7.17  0.43  4.32 9.00  1.28  271.0  24
Mulder      4.14  10.97 ***   2.30 5.72  1.47  137.0  22
Zito          3.18  7.20  0.37  4.24 9.95  1.27  170.0  22

New Aces   era   h9    hr9   w9   k9    whip    ip     age
Harden     2.99  6.46  0.40  4.06 10.89 1.17  337.1  21
Haren       3.15  8.49  0.89  1.63 8.76   1.12  474.2  22
Blanton    3.33  8.60  0.52  1.68 8.33   1.14  365.1  24

Here's their first seasons with 30+ starts.

Old Aces   era     ip        h       k     bb
Hudson     4.14    202.1  169    169   82
Mulder      3.45    229.1  214    153   51
Zito          3.49    214.1  184    205   80

New Aces   era     ip        h       k     bb
Harden     3.99    190.2  171    167   81
Haren       3.73    217.0  212    163   53
Blanton     3.53    209.1  178    116   67