My understanding of the situation was that they had to design for 2 very different mission profiles depending on the launch vehicle, which was very burdensome t

My understanding of the situation was that they had to design for 2 very different mission profiles depending on the launch vehicle, which was very burdensome to the engineers. The implied politics as I could infer, was the requirement to design for use of SLS as a launch vehicle (naturally, for a NASA mission), which some engineers had low expectations of being operational in time.