Frank Thomas compared to Ted Williams and Co.

What will Thomas do at age 38?  Some have commented on the aging flops in bay area history.  So I looked up the "most similar players" to Frank Thomas (career-wise through age 37) based on baseball-reference.com:
   1. Jeff Bagwell (884)
   2. Fred McGriff (872)
   3. Larry Walker (829)
   4. Duke Snider (818) *
   5. Willie McCovey (812) *
   6. Rafael Palmeiro (790)
   7. Reggie Jackson (790) *
   8. Ted Williams (789) *
   9. Willie Stargell (779) *
  10. Ellis Burks (765)

As you can see, Thomas is HOF--first ballot to me, but a shoe-in for everyone else at the very least.  The list is made up of HOFers and aging stars, so what did these players did at age 38 (except Bagwell, next season, and Snide, retired)?
                G      AB       R       H     2B     HR    RBI    BB     SO      BA     OBP     SLG
McGriff    146    523     67    143     27     30    103     63     99   0.273   0.353   0.505
Walker     100    315     66     91     20     15     52      41     64   0.289   0.384   0.502
McCovey    82    226     20     46      9      7      36      24     43   0.204   0.283   0.336
Palmeiro  154     561     92   146     21     38    112     84     77   0.260   0.359   0.508
Jackson   143    525     67    117     17     25     81     55    141   0.223   0.300   0.406
Williams   132    420     96    163     28     38     87     119     43   0.388   0.526   0.731
Stargell   122    390      60    115     18     28     97      50     93   0.295   0.382   0.567
Burks       55     198      27     52     11      6     28      27     46   0.263   0.360   0.419

average    117    395     62    109     19     23     75      58     76   0.276   0.369   0.509

Is this a realistic expectation of a DH? 38 yo DH? 38 yo DH that, by my calculation, would make at most $1.8 million with that line of stats (assuming he does not go on DL but miss the 400 AB bonus)?  Without looking at the ratio stats, which would be inflated by players with productive seasons with lots of AB, the 40+ XBH alone is definitely what the A's needed.  I personally love the signing.  The history study dampened my expectation for the Big Hurt, but the bargaining price made it still a very good deal.