I'm wondering if we are all guilty of this strategy, although I never rely on this entirely it has recently been useful at times.
In a recent game I was struggling to take a Flood world that was overflowing with captured ships from the AI faction and its own flood spores and turrets, I first tried a Valiant class cruiser for its Nuke ability and surprisingly the ship was almost destroyed on arrival before being infected, not wanting to face defeat I changed strategy this time with a mixed group of cruisers and destroyers thinking the varied amount of firepower would make a dent in the flood defences, no such luck, the majority of the battle group was destroyed with the survivors being turned and added to the flood defence, for each failed attempt I was making the flood stronger by gaining my more powerful ships. I then went back to my first strategy this time with my most powerful ship, a Thermopylae-class Super Carrier, this time though the ship had survived entry while getting its ass whooped I instead gave it a simpler task, to destroy the captured Valiant to save me grief in future attempts. So after all this I finally resorted to a mass frigate manufacturing from three other shipyard equipped worlds and constructed a combined fleet of 100+ ships, this changed everything as the majority of the fleet was allowed to advance while a small fraction was either destroyed or infected leaving the rest of the fleet to do its job and take out the flood spore ships and turrets. At this point I brought in my patiently waiting fleet of cruisers in a nearby system and start the planetary bombardment.
So it’s possible to use frigate spam strategically but to never rely on it to solely to solve every ship to ship encounter since frigates are cheaper to replace than cruisers they would be nothing but cannon fodder.
