I mean the movie as it exists now is like 75% fictitious (he met his wife in his 20s, there was no affair, his museum burnt down a bunch of times, Zendaya and Efron weren't real people, he didn't retire to be a father) so I don't know why they didn't just full hog on making things up. I think having a made up story about Barnum is very much in keeping with the spirit of Barnum.