[PvK]

Originally posted by sachmo:
But wouldn't the increased number of attacks created by a greater number of ships overcome the increase damage done by the large ship's heavy mounts?

Only if you spend much more time and resources building the smaller ships. The cost of engines and ship control and sensors for the smaller ships is the same, or nearly the same, per ship. This would make larger ships a good idea even without mounts (see Space Empires III).

There are some other minor advantages to smaller ships (e.g. defense modifier, lower build time, number of targets, number of firing sources), but these definitely don't overcome the advantages of larger ships, in most cases, in the unmodded game. Rare exceptions are when the to-hit bonuses temporarily hit the edge so the smaller ships become nearly unhittable, and when the enemy has a weapon you currently can't counter which can take out an entire ship in one attack, like an allegiance subverter or an engine-destroyer when you forgot to include supply storage.

Some mods restore some uses and effectiveness to smaller ships, though. See Proportions mod and AIC mod for example (and probably P&N and Adamant, I would guess - any mod with Quasi-Newtonian Propulsion will help at least somewhat).

PvK