My experience is similar in that more than two or three people in proximity are typically problematic. And the issue is that my wife typically gets left out of the conversation, or there are multiple conversations going on and she can't follow them. It has gotten so bad that one time, before her aphasia was so bad, she screamed and told everybody to leave the room. Whenever I know someone wants to visit, or we go to a restaurant, or we go to visit someone else, I tried to arrange for no more than than two others to be in close proximity. The one exception was that four of my wife's college housemates came to visit this past summer and she was thrilled and engaged, but they all went out of their way to make sure she was included.