I tried to kind of alleviate this by tinkering with weapon damage. (The fruits of my very ill-balanced and maybe to extreme attempts so far can be found here:
https://steamcommunity.com/sharedfiles/filedetails/?id=819181015)
Essentially, the most straightforward solution to this seems to be lowering weapon damage, thus locking fleets in combat for much longer and allowing smaller fleets or stations to stop an enemy from advancing until they can be reinforced. The AI kinda-sorta deals with it, but not well enough to make it viable on its own.
What I would like to see are fleet formations and stances, e.g. allowing small task forces to fight holding actions against larger fleets or letting larger fleets engage more methodically, with picket/skirmishing ships moving ahead of the main force.