A Feat that combined Dwarven Weapon Training and Dwarven Armor Training would be handy. Even just "pick 4 Martial Wrapons. That would allow my Orc Sorcerer with Dwarven heritage and culture to wear Medium Armor and wield an Axe. Or a straight Dwarf leaning unto stereotypes, or any Background for a non-martial character coming from a martial cultural background. So, cultural Frats have potential, even to be the main story of a PC.
Alternatively, a Feat that grants some of the magical abilities of a Race can help with getting that hybridization across (Dwarces with Fey Ancestry amd Misty Step? Orcs with magical wings?). So it seems like something that could be part of the system.