Am I confused?

I just had one of those "down the rabbit hole" email exchanges that leave me doubting my sanity.  I'm working on an online mystery which shall remain nameless.  This month's block is 9 1/2" unfinished, laid out like a nine patch, with piecing in the center and edges and plain squares in the corners.  The instructions said to cut four 2 1/4" squares and sew them together in a four patch for the center of the block.  It also had you sew two 2 1/4" x 3 1/2" rectangles together to make the edge patches.

The block is supposed to look like this:

Now, the corner squares are cut out as 3 1/2" square (3" finished), so if the block is 9 1/2" unfinished, the rest of the parts of that blocks better also be 3 1/2" before joining them (3" finished) or it won't turn out the right size.  But when you sew two items together that are cut 2 1/4" the resulting piece is 4" wide, right?

Am I confused?  Am I crazy?  If you sew a four patch of 2" squares together you get a 3 1/2" unfinished patch.  If you sew a four patch of 2 1/4" squares together you get a 4" unfinished patch.  If you sew two 2 1/4" x 3 1/2" rectangles together you get a patch that's 4" x 3 1/2".   And if you use these to make that nine patch it will be 10" unfinished, NOT 9 1/2".

What am I missing?