The ISC are not cheese!!!
It's just that the ISC built "the best given starship in any hull class", ie, we have the best CA, CL, DD, BB, etc. etc.
They're built so good, in fact, that they can take on ships "one hull class" bigger than them...
I-CAZ vs many BCHs.
I-CSZ vs. CCs
etc. etc.
And I thought cheese was purely defined by the number of gatling phasers and G-model drone racks your ship carried...