From 1990 - 1999 (the period I mentioned in my other post), Griffey had more hits, doubles, triples, home runs, runs and RBIs than Thomas. He also had a better slugging percentage, though Thomas edges him in avg. and on-base percentage.
Overall, Griffey's stats are superior.
Now factor in that Griffey won the gold-glove virtually every year, and Thomas is a terrible first baseman who DH'd 33% of his games during that period, and it is a pretty ludicrous comparison.
Here is the stat comparison:
Griffey vs. Thomas, 1990-1999