I believe this applies for both the parties as well - 'If the girl is slightly or even more well off, there are many grooms who will compromise more easily too'.
In love marriages, this category may not apply as it's "what the heart wants" so age may not matter here. In an arranged marriage, it can go upto the comfort level of the people involved, as some may not have a problem with a few months or even a 10 years difference, but for some it may be a big deal. It's important to respect this. Thats just the first level of selection in terms of age. The main criteria is to get to know this person n understand their level of maturity as a person, groom or bride, n check if there's atleast a decent amount of compatibility n attraction.