Bonk. I am a casual player nowadays, and I've only ever had one assigned ship. Yet, I find that I can often have an effect even when flying a light cruiser.
For example, one evening on GW1, I logged on, in my CWLP, to find that the base captured by the Lyrans on the Kzinit border was under attack by 7 Kzinti players, and I was the only Lyran on. So, they drafted me in 1s and 2s, and I defeated every single one of them, some by chasing them off the map, some by destroying them and some were captured, thus securing the base for some time. In the end, the base was captured some time later (after I'd gone to bed). Prior to the disengagement rule, I'd have lost that base quickly despite defeating the opponents.
I still say that pvp needs more importance placed on it, by having a small number of VPs for destroying/capturing enemy players, a la RDSL. Perhaps impelementing this could allow for the removal of the disengagement rule?