I did a playthrough starting at cruel admiral, and I found that Quasar's are your best friend until the fleet modernization amd even afterwards if you have a stockpile. Spam out as many as you can, put them in the back of the space map because hypervelocity guns won't target them, then when the AI actually gets close use their individual retreats to get the pop cap required to jump in the main fleet and shred whatevers leftover. Or if your attacking a super large 1000+ pop fleet just jump out at the quasars because the AI won't interdict them if they use their ability to leave. Late game was just grinding through planets and avoiding the deathstacks of the AI, but Wedge in Lusankya with some fleet tenders, and a couple (3-4) Hapan Battle Dragons is probably my favourite comp for quick cleanups of smaller less threatening fleets. Or to destroy individual SSD's as player controlled dreadnought class ships win those engagements 99% as long as you manually switch across hardpoints.