I guess it would be a slicing action since the knives are at an angle.
So are these cutters indexed or is there some sort of alignment tool?

yes I am pretty sure they are indexed.

I like the idea of buying the cutter head separately. You could start
out with a normal planer or jointer, then upgrade later.

yes that's the way. someone was telling me the cost of the grizzly head
separately and it was more then the jointer (G)

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