I would sew the blocks in straight rows as we look at the pattern in lieu of the 25 patch block and pinwheel block version and set in diagonal rows (IMHO). Like the comment just above, doing the 25 patch block, then sewing the 2 HST (made like the Boston block for an easier way) to each corner, sounds more my style of sewing the block. Your quilt will be interesting and will look forward to a pic of your final work.