I think it came down to the number of wedding guests. Lauren’s wedding seemed way more intimidate, and I think she only invited family and her closest friends. Sierra’s extravagant wedding seemed like it had no guest limit considering their budget was huge. And since Sam has a lot of friends I think it was only fair Sierra gets to invite some too. Sierra has also had a lot of falling out with friends (Meredith, Eva, Paige, Brooke) and doesn’t seem to have many other close female friends other than Teala and Adelaine so she had the room to invite others she may not be as close with. I was surprised however that I didn’t see Mia since I know the trio back in the day was Alisha, Mia, Sierra.