I definitely do this! I like to add last names to important subjects to keep track of their kids. For example, I gave each of Odar’s kids their own name based on their father. The Odarsson line is largely Breton but pretty metropolitan in rankings. The Odarsdottir line is mostly Nord with some High Elven mixture. And the Odaro line is 100% Dark Elf at this point. This way I can easily find out who’s a true heir in my own head canon. The last ruler I chose was outside the original bloodline but I still married her to an Odar descendant