I agree with all of this, if we add more voices in general, Steve Blum would be perfect for Half Orc PCs, since it has that grittiness to it that Half Orcs are known for.
I would like a bit more gruff to the voice. For Dwarves, you almost need a thick accent with the DEEP voice for the male. For the female do the same accent and just a deep female voice. Truth is you only need one voice actor for this. Find the perfect voice actor, male or female and then use AI to create the other gender of that voice.
Tbh, the default female Durge voice could fit a female dwarf or half orc and is also in the category gender fluid, I would say. I used that voice on one character and it sometimes sounded like a male, sometimes female and sometimes, I didn't really know.
Generally, yeah, more voices are always good. Since Tav/ Durge doesn't say too much, I think, it would be doable.