The "Match Edges" sets the spacing on one side of each of two edges you select on opposite sides of a connected vertex. I gave a previous picture on suggested edges to match edges, but you can try lots of edge pairs connected across a vertex:
Use "Blocking > Move Vertex > Set Edge Length" to directly set the blocking edge length.
You can also use "Set location" in this menu to set xyz locations of vertices.
The block splitting you are thinking about is called an O-grid, but you don't need to do this in your blocking because the entire farfield region up to touching the blade is an O-grid type. You don't need to split through a radial edge as in your last picture because it's structurally the same grid. You only need to control the node spacings and ratios on the radial edges of the O-grid to control the growth away from the blade.
I have said this many times: Your blocking structure is good; all you need to do is control the spacings and ratios on the block edges to get good growth and smooth transition between blocks. You cna do this entirely with the "Edge Params" button. The "Match Edges" is a convenience function.