I've tended to assume that Henry has only recently come onto the marriage market, because he's not old enough to have been ordained for more than a year, and he's been intended for the clergy for at least 10 years (based on how long ago the general set up the Woodston kitchen garden "for the benefit of my son"), and the general's keen that all his sons should have careers. Establish Henry as a clergyman first, and then see about marrying him off, sort of thing.