I don't see this as a problem in the slightest. There are an immense number of counters including fighters, missiles, your own fast frigates, and flanking. You can acquire all of these counters ridiculously early to boot. More to the point, I appreciate that there are other play styles beyond lumbering slugfests, and also that the AI seems reasonably capable at executing kiting tactics in addition to accounting themselves well in slugfests. It's a fleet archetype you need to be prepared to counter or run from, just like carrier fleets or giant capital fleets.
What does annoy me is when forces that have clearly lost no longer engage in the fight, but also do not retreat. This is a tricky problem, because if the AI is too apt to retreat you'll never have the opportunity to engage in enjoyable decisive battles. The solution that seems most reasonable to me is to have at least one capture point on every tactical map, and further to have each net held capture point degrade the opposing teams CR at an accelerated pace. Small maps could have a single capture point whose only effect is to trigger this mechanic.
If you hold the field then the enemy should either challenge you or leave. Since we want to be careful about forcing the AI to leave too early we can instead give them the duration of the CR to hang about, but give the side that holds the field the advantage in that race in the event of a stalemate. Hopefully this would allow for decisive battles to occur while cutting down on the need to chase a frig around for 10 minutes while further leaving the wolf just as dangerous as it is today if it is capable of actually being a threat in the given situation.