That would definitely strain possibility. Even if they were marching through friendly territory that would be a stretch but through hostile territory with Emperor in tow? That would be asking for disaster that the Empire cannot afford.This is a great victory, but you know what would be cooler? A roman-persian army marching all the way to the pacific. Marching through china and ending in nanjing would be preferable, but going to Island Asia is probably the more realistic one.