As a medic, do you find it difficult to get the opportunity to attend resident military courses, other than field san?

I too experienced that through out my career. It is very frustrating. The conclusion I realized was many units don't send their medics to those schools because they don't want their medics to be taken off their duties as a medic. Medics are one of the few positions in an Infantry/Armor unit that actually does their job in garrison and in training exercises. So, if medics are tasked to other duties, they are taken off the job.
And, many times, the 1SG/CMD team wants to take care of "their kind". I can tell you many stories about confrontations I've gotten into with leaders and those in the way of getting my Medics into those courses.
Set up an incentive plan, with buy in, from the command. Us APFT, Weapon Qual etc as incentives to get your hard chargers in those courses.

Wally

I have never had an issue, you gotta bend the ear of someone with their foot on the pedal, try to get training way out and project the training.

SSG Michael Hathaway , just keep fighting for yourself and your Soldiers. When I was in Germany our unit sent us all to Hazmat/Safety/EO/UPL, etc... but I've been in units where medics had to fight. Sometimes units will say they want people with longevity to go to these classes to be s force multiplier. Just keep fighting, don't give up. All it takes is for one individual to change out.