[Rigelian]

The problem is mainly that concentration of firepower is so important.
Perhaps if there were more specialty and "splash damage" weapons, that would be effective against large concentrations of ships, but next to useless against small/scattered forces...

I think you've interpreted my comment as talking about the tactical when I meant the strategic.. but what the heck, both are interesting

At the tactical level, SE4 does indeed impose what is in effect a 'stacking limit' by having one ship per square. This does result in some nonsense with large fleets, but not a bad idea overall. I remember imposing such limits in old hex-based tabletop games before now, with positive results. And as you say, bringing in 'splash damage' can discourage stacking without an arbitrary rule. I seem to remember SFB ship explosions having that effect.

At the strategic level, what I meant was the dispersal of the fleet over the empire, and the opportunity for many small scale actions (as opposed to mega-stack, win-or-die, apocalyptic clashes). I think one major factor discouraging this is the warp point system, which channels all travel through classic 'choke points' and practically guarantees only major fleet actions.

In over 20 years of gaming I have yet to find a campaign system that generates interesting cruiser actions, in any game - so the lack of it in SE4 is not a major criticism. It remains one of the reasons that I prefer the early game though, and why I like High tech cost to prolong that...