I think it must be overestimating (way overestimating) the power of some of its ships. I was just facing an experimentalist and for regular attacks it basically only sent 5 ships a wave (level 7.3), the waves usually had a shield booster, a munitions booster, a decoy, a flagship, and some other random ships. Of course that was at progress 1 - 100, I didn't keep playing that game though as it seems I love the early game so much more than the middle game that I get bored to easily.