if you make the weights equal to each other and set the fleet points (the min and the max, too) exactly as they are together then you will get one of each.
if you change one of them for 2, and raise the fleetpoints (min and max) by the ship's slotcount then you get 2 of that ship and 1-1 of the others.
and so on... you can set the fleet as you want.
I'm not 100% sure... just 98% 
good luck
neterw
