Timurids were an empire out of northern India, lead by Timur.

They existed historically, they did use elephants, and even put cannon on a few.

My only issue with the way they are presented is how fast and accurate the elephant artillery fires. Actually they aren't that accurate thankfully, but they fire enough shots at once to cause problems. But they should take longer to reload... it's 2 guys on an elephant trying to use a muzzle loading cannon, they shouldn't be able to outspeed non mounted crews on loading. I know they are serpentines, but even so... it would be awkward.