You said "they are arriving" is it a (_row Robbin) project? If so, one way is to wait until you have all of your rows, measure each one, then using the length of the longest make each one that long. Once you can lay them all out you will be able to see what to add to each to make them go together and look good. You might be able to add sashing between rows that can (wrap) around the next row to bring it together... There are many ways to fix this, it is easiest to see/figure out when you can see them all.