The new AI would be loyal to the AI that built it. The question was whether "complete subservience and complete intelligence" can coexist. I'm proposing a thought experiment which I believe suggests they can.
But if it's possible to bespoke-construct a fully loyal AI, it should also be possible to train a fully loyal AI. The problem comes with verifying that it is loyal, and I don't have a solution to that one!
I just don't think I agree that loyalty and intelligence are inherently in opposition.