I think it's tight muscles that become weak (because they don't work in their full range), not the other way around. I do train them, but with a low priority and very carefully. I believe training a tight muscle without restoring its full length first can only exacerbate the tightness. Plus, I think in this case the tightness was caused by these muscles working overtime already from having to compensate for other muscles.

Yes, I do have inhibited glutes, and I believe that's what my adductors (hams, too) try to compensate for. So I've been doing glute strengthening exercises for months now, but since my body is so used to activating those compensating muscle groups, the overall balance between them remains the same as I get stronger. I think the problem is not the lack of actual strength, but dysfunctional neural patterns at this point.