If there are different mediums on one subject, it seems more popular hense the human brain would natural like it more. As well as if it is on different mediums, it can get to people faster like if one person only like poems, they could get into the painting via the painting. I hope this helps. ;)
Justinian I failed to regain all of the former provinces of the old Roman Empire really from a combination of all these reasons, but the main one was that he made military blunders.
