I think he does that a lot. His whole process is not premeditated at all. He himself once compared it to automatic writing and it explains why so many influences appear multiple times and seem only loosely connected. They're only linked via association.I actually entertain that possibility too. And I sometimes wonder Morrissey, consciously or subconsciously, blends different experiences / lyric together in one song.
For example I wouldn't be surprised if the parallels between Billy Budd and Hand In Glove are in fact not intentional. Maybe they just "happened".