Good luck! I really hope all the very best for you and that we hear soon that your mare is preggers!
It’s not so much that anyone is “against” LC, but against the idea that her vet thinks this will solved the OP’s problem.
As others have pointed out, this mare simply isn’t being properly monitored in a way that is appropriate for conception with shipped semen, which is probably why she isn’t getting in foal.
And the OP’s vet has so little knowledge about equine repro that the best he could come up with was “live cover” as a fix – basically suggesting the OP give up her breeding to the stallion she REALLY wants and using a local stallion simple because the vet doesn’t know how to do his job.
BTW, I have to note that the OP’s vet certainly isn’t the only one who falls back on LC if the mare can’t get in foal.
I have 2 different friends in 2 different states who are getting the exact same advise from THEIR vets…:no:
You know, I wish there was some way vets could be honest on exactly how much experience they’ve had in certain areas of practice. Certainly would save many of us bundles of $$$$…