hmm, how about: If your primary attack is less than 3, roll one additional die for the difference between your primary attack and 3, up to a maximum of 2 additional dice.
Or, similarly, instead of buffing the strength of the ordinance (which I do NOT think is the issue--protons and adv protons hit hard), you could decrease the cost with the same formula:
If your If your primary attack is less than 3, decrease the cost of any torpedo or missile with an attack value of greater than or equal to 4 by 1.
Make it a mod and call it "Bomber Loadout" or whatever.
Edited by quasistellar