Many things have happened over the years on The Walking Dead that have required suspensions of disbelief; a guy wrestling a tiger into submission in the zombie apocalypse may have been too much.
His characterization hinged on whether or not there was more to him than a man who called himself king.
Plus, it explained how the hell he had a tiger.
It makes sense that the casting crew would want to use Ezekiel’s monologue from the end of Episode 2 to figure out who was right for the part.