I've seen a bow with only a single ring/limb, and it still drew in the 60#'s. Should be excelent stuff.
for yew however, you want as much as rings/inch as this indicates a heavy s/g.
yew staves, with a decent length (80") and a high rpi (more than 50rings per inch)are worth a fortune. They're in high demand by warbowmakers.
Nick