Clomiphene and nolvadex are also both used in estrogen positive breast cancers, not just a fertility drug.
Citations of this for clomid seem to be getting sparse.
Nolvadex works just as well. If a SERM fails to increase LH/FSH, there is something wrong/abnormal about the top end of the HPTA. In that situation in a TRT context, hCG is the only other common option to maintain the testes; but that could have limited fertility benefits in some cases and then hMG would be a option that is costly. https://en.wikipedia.org/wiki/Menotropin