In this case, I don't think so. His issue isn't the choice of AI or likely the dose. His issue is that he started a cycle of an aromatizable compound at a high dose without using an AI.
Now that he presumably has gyno, he needs to keep E2 at a healthy level and start using Ralox (or Tamox) to try and reduce the gyno.
As for the effects of Tamox reducing the effectiveness of Tamoxifen, that has been exaggerated and may not even be a concern. Jimithing has posted medical studies on this.
As for aromasin, it is a weaker AI than adex. And it is rare to not respond to adex. Plus the fact that his issue is starting the cycle without an AI.