So, how about we make Freighters actually something of an auxiliary vessel for snub fights? They are already pretty well at just warding off attackers while the one attacking can break off at any time and he wouldn't die because most freighters don't pursue or some don't have a CD. If they could only mount turrets (maybe even only some special turrets for freighters) and had their core regen buffed a bit, they could make for cover when a teammate is getting focused. Frankly, the freighter wouldn't work too many wonders when it's focused by many snubs, but maybe something else can be arranged to make them a bit more viable than a gunboat in such situations because the freighters are smaller.
The issue is that they are also, at least in theory, trade ships. I disagree that they shouldn't be able to defend themselves, because it would be senseless in a dystopian future like in fl to leave the safety of a planet or installation without a good deal of firepower. Freighters aren't supposed to need escorts. Transports, on the other hand, are large and slow, and therefore need escorts. Thus a combat buff for freighters would also make sense in that regard. However, to do justice to the trade aspect, they would need to be given something that makes their usage worth it. There is no reason not to use a transport instead of a freighter, which is the key problem.