I think we all have been through this dialogue with the A and in our own heads.
Living in the situation made it harder to detach and allow him to have his opinions and maintain my own opinion. At some point my husband caught on then that became the issue - we have so many different opionions and nothing in common etc. (and all the time it became clearer that of course an active A and a non A would not agree on much nor have much in common)
Living apart really allowed me to see and hear more clearly the crazy making arguments and detach without much emotionalism or disruption. When he got sober, some of it continues and so we are still not under the same roof. I discovered that the distance allows us both to withdraw and review our positions and take more responsibility for them without putting it on the other.
I suspect the place to begin is to believe in yourself and your opinion - rt or wrong - it is allowed. You have to allow the same for him. If it results in a decision getting stuck then consider step two which is to find a compromise and let him quack if necessary. Just set the boundary that his quacking about you has to be done outside of your ears. (I used to do that and it was funny the ways he would attempt to do this - I also did this with my kids when they were teens and it really helped me) Hearing things from another room gave me the space I needed to translate and let go.
It can be a very difficulty place to be, but the remedy is within you and beleiving in yourself. Go with the notion that you are right and if you need to compromise you will, and if you can't then let him deal with that. Stop trying to make him do what you think he should be doing - he has to figure that out.