Just drawing the situation out, even roughly, is already an enormous step forwards from theatre of the mind, and is doing most of the heavy lifting here. It’s also not “theatre of the mind,” like the original poster is implying. It’s a map, just one without grid-spaces or precise distances.

This works for situations where exact positioning isn’t too important. When want to have AoE spells, move speed, flanking, and battlefield control, it generally because difficult to ensure that the GM and the players have the same picture of the battlefield. Even just drawing it out roughly can help a lot, but pure theatre of the mind really works best when you only care about distance rather than relative positioning and complex battlefield conditions.

If it applies to DnD’s cosmology, than it has to mean with viable offspring, because half-dwarves canonically exist in the Darksun setting and they’re called Muls.