I cant comment on the personal motives behind the three marriages.. However the thing is that polygamy is halaal, afterall! Its just that Allah has conditioned its lawfulness with ones ability to treat his wives with equity. Hazrat Wala db says that this condition is difficult for most of the people to fulfill; thats why he generally discourages people from marrying more than once. Wallahu A'lam! This is what i know so far. If I will get to know more about this, i will post it here, Insha-allah.