Usefulness of the bigger mounts

[Alneyan]

While designing a few Light Carriers, something stroke me when doing a small calculation about the compared efficiency of the Heavy and Massive Mounts. Here are the increases in damage compared to the previous mount:
- Large Mount compared to no mount: +33% damage for the same space.
- Heavy Mount compared to Large Mount: +12,5% damage for the same space.
- Massive Mount compared to Heavy Mount: +11,5% damage for the same space.

So, while the Heavy and Massive Mounts do increase damage a bit, is it really a good idea to have fewer, albeit stronger and bigger, weapons? It will make them more likely to get hit instead of, say, these Fighters Bays when speaking of a Light Carrier, or other less critical parts of the ship.

Besides, if the chances to hit the enemy ships are not impressive, I guess you would want to have as many hits as possible, rather than the occasional hit dealing a lot of damage. The only reason why you would want to deal as much damage in a single blow would be against a Crystalline Empire I guess, given the properties of their armour.

So, am I missing something obvious, or are these Heavy Mounts (and Massive Mounts as well, although these are much less common) bittersweet? Or am I merely worrying a bit too much about my beloved Light Carriers?