multiple recs?

Why would you need multiple rec letters giving the same sorority all the same information over and over and over and over again??? I keep seeing people say get multiple rec letters but occasionally I see people say that you only need one because sending more is just repeating information. Can someone please clear this up???????

Like is it good to send 1 rec and like 5 or more letters of support if you know a lot of alumnae???? Or should we just send multiple recs (even though its repeating info) and a few letters of support? My mom says that I just need one rec per chapter along with multiple LOS and she was in a competitive sorority at Ole Miss so I just do not know what to do.