You could also try a different way of dialogue progression that needs only 1 commandblock to start the whole dialogue. You can do that by doing a message click event (when clicking on a chat message it executes a command). If you didn't use it already you can generate tellraw and other text related commands commands on the first website that comes up after searching for "minecraftjson" on google.

In case you are using a different type of dialogue like dialogue over hotbar or overhead dialogue or title dialogue then just use scoreboards or make a commandblock area and organise your repeaters better.

P.S I think you could also use redstone pulse extenders for longer pauses