Way to make low-poly spheres

Spheres contain a lot of triangles, and while this may not be so much of an issue performance-wise, it becomes an issue with this:

I can’t union more than five spheres together. 6+ and I’m over the limit. If 6 spheres is 2592 triangles, that means each sphere is 432 triangles – this does not scale down if you make the sphere smaller. If I’m making something tiny, I don’t need a sphere that smooth, and if I were to try to take a cube and cut slices off of it to form a sphere, it probably wouldn’t complete successfully, and if it does 200 items unioned together is not going to behave well with CSG file formats. It’d be nice if there was a way to create low-poly spheres so we don’t go over the triangle limit.

What spurred the posting of this:

The reason it has too many triangles is because I have three spheres in the union. Without the spheres, the union is only 1218 triangles which is hardly close to the limit.

I’d absolutely love a “low poly” CSG option, or some kind of slider that changes the amount things blend together/ deteriorate in small details.

I’d actually like it both from an aesthetic standpoint and a performance thing. CSG is MOSTLY used for rounded object manipulation (cylinders, spheres, holes) so it doesn’t really make sense that spheres are the biggest problem causers.