Well, I'm not sure you can actually delineate here. First off, the progressing space agency wouldn't be a progressing one if it hasn't made any accomplishments (funding would dry up quick without any promising research), and it would have to have leading figures to even get any kind of initial funding in the first place, whether or not they are/have had space related careers or are the source of funding the venture/agency.

On the other hand, an already-accomplished space agency doesn't mean you can't have the potential to become one if it's leading figures, especially as it talent moves on to other ventures or retirement.

Doing space things requires non-space financial clout, and that doesn't come with a greenhorn straight out of university or college. They may have grand plans and ideas, but... they are yet not established in the community sufficient enough to command the kinds of funds required to start a space agency on their own. Therefore, even a progressing space agency has to have accomplishments under its belt with figures capable of leading the agency to its current situation.

I think the question can be phrased better.

> Would you rather work in a space agency or a space venture?