Can you post some photos of your log?
Never split a yew log myself, as it doesn't grow locally to me. Every stave I have bought was bandsawn. I have broken down quarters into 2 longbow staves, and have used the bandsaw for that. The wood that I had was straight grained, and any major knots were not going to interfere with layout.
If the stave has a lot of character, I'd probably split it with wedges to ensure the grain is followed.
As you don't have a bandsaw, Musky's kerfing method will do good, providing you can layout your staves around the knots.
An 8" dia log depending on how clean it is should yield a lot more than 3 staves, especially if you make Elb's..