Best way to manage a large amount of Page Templates

Are there any hacks or tricks to managing a large amount of page templates?

I’m adding quite a few unique pages to my site, with the plan to add more. The templates are all quite a bit different so I couldn’t really find an appropriate “template” page to use for them.

Is there a way to manage the listings of the “templates” inside my wordpress install?

I was going to name all of them “z – template name” so they appeared at the bottom of the list, since they’ll only be used once. Leaving the frequently used pages near the top. But this seemed very “hacky” so I wanted to know if there’s a better way.

Lastly, for conditional tags. I want to enqueue custom spreadsheets to a few of these pages. Will adding a lot of spreadsheets with conditional tags slow down my load speed? (Ex. if I had a conditional tag with 14 spreadsheets tagged conditionally per page using is_page_template( 'template name' ))

Any advice would be appreciated!