Too much of an advantage?
Relationships aren't PvP games where balancing is involved. There are thousands of couples out there where one spouse is the money maker with all the relevant skills to be successful in the real world, while the other is relegated to house wife/husband. If there is no child in the equation, you often have one spouse that is the money maker, the social networker and pillar of the relationship, while the other half's only advantage is looking pretty. Compared the two and what they each bring to the table, if they ever split up its super obvious who would be the one better off. I myself am the result of such a union, but that doesn't mean a deep meaningful relationship can't be reached.
And to the point of mental development, the man's not shown signs of ascending to a higher being or somesuch, as far as we know, he's just a very old human being. An adult woman would be just as mentally developed, maybe not as mature, maybe not as intelligent, but certainly mentalled developed. but say his ideal candidate in an adult Zatanna, if she's anything like her counterparts in other continuities, she's mature enough, and self sufficient enough to make her own decisions. You intervening would be just you imposing your own sensibilities on someone else, which is distasteful to say the least.