Can I get by with 2 or 3 to 1?

An 8:1 scarf is only 2" long on a 1/4" strip. Practically, something steeper would seem more likely to fall apart when you have to spring a strip in.
They take the same amount of time to make, and in the end,if your scarfs are an inch longer you'll just have slightly shorter scraps to feed in the stove .

I am assuming you are scarfing through the thickness of the strip. I don't have any experience with going across the width and in that case, you would do well to ignore my advice.