Yeah, the problem here is seeing them as 'routes' in the first place, when they aren't really. It's not like Persona where you spend time with the person, and then if you make the right choices they become your girlfriend.
Even if you go down the Aerith 'route', you still get Cloud remembering Zack, his only best friend for a while there, who he now remembers is dead, and who was head over heels for Aerith. On Aerith's GS date, Cloud declines her invite to sit next to her, and during the date she proceeds to say: "Cloud, you're not him, but that's okay", and then "just until the end of the ride", real romantic.
Even on the 'non-optional dates', if you can even call them that, she spends a bit too much time speaking about Cloud and Tifa's relationship with each other for these to be considered 'dates' between Cloud and Aerith. These aren't candlelit dinners they're on together...they're spending like 3 minutes talking with each other in whichever place they are currently (mostly about Cloud and Tifa, at that)
Also, if you choose the Aerith 'route', there is still an abundance of Cloti development throughout literally the entire game, bar the last chapter. And as I said, most 'Clerith' development is hardly even Clerith.
In short, there are no 'routes' here, you can choose to see more Cloti, or not.