split part into welded assembly

I'm trying to split this impeller into a multi bodied part to create an assembly to be welded together. The impeller vanes and disk will be plasma cut as shown by the 3d sketch. The keyed shaft needs to be a separate part as well. My initial approach was to use a 3d sketch to create planar faces, then stitch them together and use the split tool. This is somewhat tedious as I would need to do it for each impeller vane. Is there a better way?

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