HCG does more than you think, it not just simulates LH (and FSH a bit) it has a profound effect on number of other hormones- it fasten up thyroid and adrenal etc- and one of downsides is that it aromatise a lot (depending on functionality of testicles) so it does create negative feedback. Now you may say that clomid will fix that but- it will not, as otherwise we would use clomid during cycle itself, but unfortunately it just does not work that way.
In any case- I would not suggest using HCG during PCT.