The tables that list the number of units will not accurately reflect the fabric combinations you need. At each step, just make sure to use half of the units from each FQ fabric. For example, consider the fabrics that are used in only one mid-mod shape. You have two B1 units and four B2 units. Use one B1 in part 1. Use one B1 unit in part 2. Use two B2 units in part 3. Use two B2 units in part 4.
For fabrics with 1 mid-mod shape block, you’ll need 2 each of units 1 through 4.
For fabrics with 2 mid-mod shape blocks, you’ll need 4 each of units 1 through 4.
For fabrics with 3 mid-mod shape blocks, you’ll need 6 each of units 1 through 4.
For fabrics with 4 mid-mod shape blocks, you’ll need 8 each of units 1 through 4.