My ideas:
I hope they could maybe think about this idea a bit. I mean not all cultures marry for love. That's a Western thing. I mean as Tevye in
Fiddler on the Roof says "Our old ways once were new weren't they?" and he's right. In the hunter gather era grooms would 'take' brides. That's where we get the best man from. Then in Mesopotamia (maybe earlier)Girls were their dad's and then their husband's property. The dad would arrange matches for his daughters. Sure the peasants married for love in the Middle Ages but the royal and noble girls were still in arranged marriages. It wasn't until like around the 1800s (or a bit earlier like the 1700s the 18th century) that the notion of "love" came into play for then non-peasants.
In my examples we could have either a "Matchmaker" or an astrologer NPC (who would do the organizing of matches) But please remember no matter what happens both the people can break the agreement with the other family. Of course there's is always the option of having a "Bollywood" Wedding. But at least having the option of arranged marriages is good for storytelling isn't it?
In my examples I will be playing the girl's family. But it could work the other way around too
Example 1)History style (kind of)
Isabelle and Bobbie are both babies. Their parents want them to marry when they are older. They contact either a matchmaker or an astrologer to see if the two are a good match. When Bobbie's a child he goes lives with his future in-laws. (He would be a NPC in the house simliar to the butler in Sims 3), as a teen he will go back to his parents' house and the two sims will date (with or without a chaperone-it will be up to you the player to decide), and if they still agree with the agreement/haven't fallen in love with someone else they will marry when they are YAs.
Example 2: "Sleeping Beauty" style (kind of)
Isabelle and Bobbie are both babies. Their parents want them to marry when they are older. They contact matchmaker/astrologer. Makes agreement with other family. Kids are children now and they meet at school and when they are teens they discover they are betrothed to each other. They go on dates for awhile and if they still agree to the agreement/haven't fell for someone else they get married as YAs.
Example 3: Modern style
Isabelle and Bobbie are teens they have turned down several matches each. Isabelle's family is told by the Matchmaker, relative, or friend about Bobbie's family having the same problem with Bobbie. The two families decided to get together and the kids get along very well! They go on a some dates and then agree to get married when they are older. Then if they didn't fall in love with someone else, they would get married as YAs.
Note: The worst thing that could happen is that Isabelle or Bobbie could be disowned for not marrying (Isabelle/Bobbie) the parent's choice. So no so-called you know what.