All true!
The only purpose of a priority list is so that if you have two spells up at precisely the same time, you can look at the list, compare their positions, and cast the higher priority spell. Priority lists can't explain the mental arithmetic that explains (as you just did) when a priority list is not to be followed, I think you kind of just have to tell people the basics, explain the synergies, and with practice and understanding they learn when to ignore the rules. If I may be permitted to steal a quote from Barbarossa in an old pirate movie, "Priority Lists are really more like... guidelines"