border some of the blocks for balane even if you have to cut down some. You can use FRAY-CHEK to keep the hand stitches secure. The cross stitches will further secure them
Lay them out and arrange in a pleasing way those that would be bordered and those with just sashing. Use a contrasting color for the bordering than sashing. I believe the arrangement will work well.
Now - say you have two blocks that need borders. Then recut two more and put the four in the corners or in the center.......make the smaller blocks work in your overall design.