Which the bipedal lion was obviously derived from no? But I digress, it's not unusual for Disney to deviate from the way history had it all written.
Well, the King Richard of the animated film is based on the one that appears in all Robin Hood stories. In almost every version of Robin hood, King Richard is seen as a great king. If you read about King Rciahrd and Prince John biographies, you'll know that the papers for both brothers changed later. Even my uncle, who used to be a mason, told that King Richard wasn't the way he's described in Robin Hood tales.