Leaving the second BB alone is bad for two reasons:
You gave England a capital warship that can bombard you at will. That means two bombardments for the price of 1 infantry. (6 IPC for 3? That’s a good trade!) England is not out 16 IPC for a carrier to defender herself.
Don’t forget that the Allies don’t have to worry about keeping 1-2 Figs on the carrier giving them even more versatility





