I think having a marriage counselor that specializes in addiction is an excellent idea. My AH and I went to a counselor withOUT such a background about 5 years ago. I was horrified when she told us she didn't think AH's drinking was a problem if he was still able to function at work and was still participating in caring for our then toddler. Really? I know it wasn't nightly back then like it is now but we told her he was getting plastered every single Friday and Saturday night. And she saw nothing wrong with that? Huh? That experience really set us back and we stopped seeing her shortly thereafter. (AH hadn't wanted to go in the first place, was suddenly justified in his drinking and happy counseling was over.)
Fast forward 5 years and the drinking was out of control and occurring nightly. He could no longer deny he had a significant problem. As a last attempt we started seeing a new counselor WITH an addiction background. She was awesome! She didn't hold back on her assessment of AH or me. Helped me understand my enabling and most importantly gave us specific things to do. I started going to Alanon, read a lot of materials, set my boundaries and am now working on detachment. Unfortunately AH only made it to 1 AA meeting and decided about 4 sessions in that he was done with counseling. We are now in the processes of divorcing.
I continue to see our counselor though and it's really helped me in my quest to become the best version of myself.
I hope you and your AH both find it helpful! Good luck & keep us posted.