Tremendously better? No.
Batting avg: Cobb (.366) Williams (.344).
Cobb led the league 12 times in hitting to Williams 6.
They both led the league in RBIs 4 times.
Williams led te league in runs 6 times to Cobbs 5.
Cobb led the league in hits 8 times. Williams never did.
Cobb had much more doubles, triples and overall hits.
So as a pure hitter? There is no argument you can make to say Williams was tremendously better. A really good argument could be made, based on stats, that Cobb was the better pure hitter.