Are you making a pack that you're trying to utilize connected textures in, or are you using someone else's pack?
In either case, that's not how connected textures in Optifine works. Optifine uses a set of 47 pre-made textures by the pack-maker for complete control over the look of each connection. It also allows for advanced controls, such as nesting effects. You can randomize certain pieces of connected textures, you could connect certain repeating parts of connected textures, etc.. However, all of this requires textures made and rules set by resourcepack makers. What you're suggesting is both unreasonable and unlikely to work to the very particular tastes of most resourcepack makers.
All of this being said, your complaint is better-aimed at the resourcepack authors, not the Optifine creator's.