No, cruisers were not trying to kite. That might make some difference. Scaling should favour Seraphim cruisers because of splash, but otherwise I don't think it would be a big deal.
I did some more tests vs other air. Short version: T3 air usually beats cruisers. T2 torp bombers are much more cost effective than gunships. Seraphim cruiser is good vs T2 but bad vs T3 air [not counting T3 gunships].
Methodology: as before. No micro of cruiser or air. Always one cruiser.
Aeon strat bomber vs cruiser: beats all; remaining HP: Aeon: 40, UEF: 1800, Cybran: 1040, Seraphim: 2620.
UEF strat bomber vs cruiser: beats all but Aeon (cruiser wins with 248 HP); remaining HP: UEF: 2000, Cybran: 1930, Seraphim: 2820.
Aeon T3 torp bomber vs cruiser: beats Seraphim with 610 or 3150 HP remaining (2 tries); in all other cases both die.
Four T2 torp bombers (one from each race) vs cruiser: Aeon wins with 416 HP, Seraphim wins with 266 HP, UEF loses with 1 or 3 surviving bombers, Cybran loses with 2 surviving bombers.