This kind of event wasn't mentioned anywhere in Atlas' original plans. He actually wasn't planning to "build" Pangea at all until everything was over. It was a Society he formed on his own, but he never planned to take full ownership of it.
The offer that came from Alkatiya was to provide forces for Pangea that would be loyal to them.
Atlas was naturally prone to take this offer, as they would be immensely useful in expanding the Society Legend. However, at the same time, he didn't quite want to accept any new members for the moment.
'That is why I must learn their intentions. If those troops can be used without directly accepting them into the Society, it will be best to take them. Then, after they have been vetted, I can consider permanent admissions.'
However, before even that, he had to see if this deal was one worth taking at all.
