Fiddler on the Roof is a show based on a Series of Short Stories by Sholoem Alchem called Tevye the Milkman.
The whole wedding scene is not in the Book. The section on Tzeitel ends when Goldie agrees to let her marry The Tailor Motel Kamzoil instead of Lazer Wolf whom the Matchmaker suggests.
Shalom Alechem came from that world (Of the Shtel) and he wrote Satire of it.
The problem as I see it , in the general world nothing is sacred and you can pretty much say what you want. You can portray any character any way you want. You can also portray people as complex individiduals . for example In the chosen Reb Saunders has a dark side. A frum book would never show a dark side to a Rav (I didnt say a sinning side, just a darker side)