What I know about H.O. track and O gauge track is that with O gauge track you have a curve diameter of 031(31 inch curve) to start with and H.O. uses a curve size of 30 inches or 15 inch radius for their smallest curve section, these are factory made size.
Also Lionel made 027 track with a curve size of 27 inches, so it is about 3 inches smaller in diameter then the factory H.O. curve of 30 inches or 15 inch radius.
There are many sizes in both O gauge and H.O. size tracks and switches. However side by side you may get more H.O. track in the same area for the corner of a layout.
Lee Fritz