Call me Robert guys
I don't recall any title that had Pikachu in it, that didn't completely revolve around Pikachu (plot wise). Could you point to an episode where Pikachu was in the title but the main central focus WAS NOT around Pikachu and was shared with other Pokemon/characters.
What I mean is they have episodes where the title might be about Ash and Pikachu but then other stuff happens to other characters in the show. I'm sure it's happened a couple of times. Or when an episode is about something else and a random event happens in it which no one expected like Lillie's egg hatching in the race episode of Sophocles getting Charjabug.