If the 10x10 doesn't work, try 12x12. You may need to add pieces to fill things out (I'd say just an extra pair of Knights*), but it's a thought.
*My first thought was Zebras, but that idea lasted about a quarter of a second. It'd add another level of complexity that I doubt you'd want, with another bunch of compound pieces -- Okapi, Bison, Kuhani, and whatever you call the Harvestman compound.
If the 10x10 doesn't work, try 12x12. You may need to add pieces to fill things out (I'd say just an extra pair of Knights*), but it's a thought.
*My first thought was Zebras, but that idea lasted about a quarter of a second. It'd add another level of complexity that I doubt you'd want, with another bunch of compound pieces -- Okapi, Bison, Kuhani, and whatever you call the Harvestman compound.