As to who goes I presume, apparently there's been issues between them for a while.
But why would they fight each other? It doesn't make sense. They had totally different jobs within the club. What Pearlman did was the commercial part, which is sponsorships, lease agreement with the council, merchandise, club shop, web site, media, tickets..., nothing to do with the footballing part. Swansea need a person who can generate money from commercial activities, and Pearlman did it well while he was at Swansea.
I always thought he would leave after a couple of years. His job was to lift commercial activities from amateur to professional level. And that's exactly what he did. I remember how our web site looked like three years ago. It was a mess. Some people complain about his wages, he was allegedly on £500.000 a year but that's what Bony earned per month for not playing.