Most battles I have had have been one sided. However, it wasn't always when I had the numbers advantage. During my end tech game, I took on an enemy fleet of mid-late level tech (anti-matter engines, soft x-ray lasers, etc) with only a handful of gunships and a couple frigates. They had about 20 or so ships ranging from 10k tons to 30k tons and they were missile heavy, wheras my gunships were 1000 tons and my frigates 30k tons. Since my gunships had heavy thermal reduction on their engines I sneaked them around while my frigates shot down missile after missile, and when they got into range of their back-most ships (just outside of their res 20 that was active) they opened fire (the gunships had 2 fairly large lasers that shot every increment each). While the enemy ships then became distracted looking for my gunships, my frigates moved up while simultaneously opening fire with missiles on the enemy. The enemy shot down a fair few of the missiles but the volleys were too dense (I use large amounts of reduced size launchers) and a lot got through killing most of the smaller designs. Both the frigate and gunships groups then moved in to mop up the larger of the enemies that remained with their beam weapons. The results: My side; 2 gunships heavy armor damage (little internal), 4 gunships light damage, 1 frigate moderate armor damage, 1 frigate light damage. Enemy; ~20 ships from 10k to 30k tons destroyed.
There were times where engagements were not one sided, but those were mostly small detachments for recon encountering an enemy and doing some damage while falling back.