User blog comment:Ofi123/Powerleveling kanmusus/@comment-62.122.80.38-20140612142123/@comment-24702213-20140630135659

Ok. Late reply but this method with BB is for:

1) Higher chance for flag to get MVP. Getting the MVP will increase exp and reduce the rate of fatigue level increase.

2) Reduce bauxite consumption. Ammo consumption will increase due to the BB, but bauxite will reduce due to all red planes.

3) When all support ships are at red, killing off the extras will not be easy with just 1 shelling phrase. An extra will let the flagship kill 1 more enemy while the others have another go at killing leftovers.

I agree the CL part is a bit off due to their low FP, but as long at the ship can double attack this method can be used. Though personally I will also go world 4 to train them.