WI Al-Mutasim continues razing Asia Minor in 838 AD?

[Don_Giorgio]

In August 838 Caliph Al-Mutasim captured and razed Amorium birthplace of former Emperor Michael II with a 30000 soldiers army as an act of revenge for the destruction of his own birthplace Sozopetra earlier by Emperor Theophilos.
Mutasim intended to continue his campaign by razing all neighnour castles to Amorium hoping to corner Theophilos and Roman army in Dorylaion but news came that his nephew Abbas al-Mamun rebelled and Mutassim abandoned his plans returning back to his capital.
WI there was no rebellion of Abbas and Mutasim was able to raze Anatolia and corner the Emperor in Dorylaion? Theophilos's army had roughly the same size as Mutasim and a clash between these too would be bloody but i tend to believe that it would be inconclusive.
What would be the outcome of this?

P.S. I am using my PDA to write as i am with my gf buying gifts...