Is the one brother really the realtor for all these couples?

Is he really their realtor? Seems like it's so unrealistic, because the couple is sitting there, and he goes off and calls with his cell phone, and then comes back "well, I got good news and bad news...", etc. and there was an episode where he went to them and said "well, the house has k/t wiring, so we'll have to add it into the budget". Wouldn't they find out these things during the general inspection? Why do these couples get the keys so quickly? Assuming they are taking out a mortgage, it should be taking at least a few weeks, and i see them get their keys while wearing the same clothing as they did when the "realtor" called about the offer.