Assalamu alaykum There were four musallah in haram. But not four separate jamaath at the same time. But sequentially 5 salah were led by four imams in their musallah. eg. fajr maliki, zuhar shafaee, asar hanbali, maghrib hanafee, eisha maliki, next day fajr shafaee. The reason was the salafees demolishing the four musallahs was that, they didn't had their representation. The fifth musallah was non-existing, so they demolished the four musallahs.