It really doesn't make a difference if you split the L vertically or horizontally. It's the same fabric, but you'd have a bigger piece if you went horizontally.
If you want to bridge the A, you've now created a problem for yourself. ;-)
Paper piecing, at least this kind, requires a full straight edge for placement of the next piece.
You need to split #9 (using the nos in your diagram) into 3 pieces.
But going left to right, after you've sewn #10, you now have an edge that goes the length of the letter.
You'd be able add piece 9A, but there is no way to pp the 9B and 9C.
So that won't work.
What you would need to do is break
ack - see next post