In fact there is a good argument to be made to the contrary. If both are teens, they will be getting married during a very powerful bonding period. They are both not fully hardened in their ways and can grow together. When older people get married it is harder for them to bend personalities.
I overheard someone saying that for his daughters he looked specifically for boys who are not mature. (I think he succeeded.) It surely sounded weird to me, but it has some merit.