Major fail by the major
I'm watching the war games scene and it dawns on me that Maggot performed competently and sanely in this.
And it then dawned on me that when Maggot broke down in the final scene, the trigger was being in the chateau, with women and partying and comfort.
Everyone knew that Maggot's weaknesses were women and luxury. So it was a huge and easily avoidable mistake to choose Maggot as one of the soldiers to go in the chateau. If they had kept Maggot far away from the chateau, then there is every chance that he would have remained focused and the mission could have turned out very differently.
Unless I'm missing something, I believe there is no answer to this question. Like so many questions about movies, the true answer is that it was necessary for the dramatic scene that followed.
If a private venture fails it's closed down. If a government venture fails it's expanded. M Friedman