Are the Clipse Missions Standardized?

We don't see missions in the department o fence flying on or being bid out for just starship, or just new glens giant faring. The differenceis, can they can they create some sort of a programme that separates the payloads and the allocation from the missions they fly? And then so if stuffs going to go to the moon on eclipse, then we can reallocate it when there's other missions available. If the clipse missions end up with more paylod space than they planned on originally, we can get a couple o other ones in. I think that that would make sense.