It seems to me it would be better to have a requirement that married candidates would have to be married for some minimum amount of time (let’s say 5 years) before they applied for the priesthood. By then, they’d have a better handle on the demands of being a husband and father, and the marriage would hopefully be on a firm ground too.
Having a young couple cope with the demands of new marriage and a guy becoming a priest with all that entails, all at once, seems like a tall order.
Edited to add, before somebody says it’s just like helping your husband get through law school, med school etc, well to some extent maybe because there will be a lot of hard work and sacrifice. However, those types of professions are going to offer the woman a reward later in terms of being the wife of a successful man with more disposable income and goodies for her and her family. Being the wife of a priest may command respect, but unless your husband manages to work his way up to Bishop or something, you likely won’t have much income and you’ll be called upon to give of yourself forever. The seminary and early priesthood is just the beginning and it never lets up.