Someone wise on a previous thread talked about how Diana brought her sons up to be equal, despite knowing that one would be King and the other a bit player existing at his brother's largesse.
Perhaps she (and Charles of course) were wrong to do this, but as a parent, how could they do differently and not bring the boys up in a really damaging dynamic? Although I don't think anyone brought up as part of the RF has any sort of "normal" family life anyway.
I believe it used to be in rich/aristocratic families that the first son inherited the title, the second went into the army, the third into the church (not sure about fourth and subsequent though) so each son knew their role and responsibility whilst growing up.
What the law needs is equality. Parliament needs to change the law around inheritance of titles and just make it first born inherits irrespective of sex, and that females can pass down their titles through their family line just as males can. It would resolve the issue of Princess Margaret's children only having titles because their father was made an Earl.
Alternatively, just scrap titles completely and have done with the whole lot. It is surely anachronistic in the 21st Century to have such feudal titles anyway.