Originally Posted by Drip

Oh, that's very possible. I just put my regular squads in the first 4 slots, some random but useful girls in the fifth (most notably: Mei Plumblossom and Cattleya, so I always start with a full blast bar), and filled the last three with the best slicegirls I had left. So I ended up with 21 slice girls on the ship, and can easily switch it to any other type by simply replacing the last three squads. But, if only 16 girls are required, then I guess I could try to make it a dual ship if that's possible?

Dual ships are not possible according to Japanese wiki. The higher amount will determine the colour of the ship, if two colours have the same amount of girls the ship will remain colourless.