Apollo wasn't all that different. It ended the successful relationship with McDonnell-Douglas which had produced Mercury and Gemini and brought in a number of d

Apollo wasn't all that different. It ended the successful relationship with McDonnell-Douglas which had produced Mercury and Gemini and brought in a number of different contractors at the same time: this was the result of lobbying and pork-barrel politics IIRC (I am not an expert). Unsurprisingly this transition set back the space program quite badly. IIRC things only really started to shape up again after the Apollo 1 fire which killed three astronauts.