I'm a bit confused about ushers and what exactly they do. My fiancé and I were trying to decide whether we wanted to have ushers and mentioned this to my grandmother. She will be directing our ceremony (for context, my grandfather is a Presbyterian minister and has performed hundreds of weddings and my grandmother has directed almost all of them) and she stated that we need ushers as we need someone to escort our guests to their seats as they arrive. Now, I've only been to a few weddings as an adult but I have not seen one where all the guests are escorted to their seats. Our wedding isn't extremely formal, and I'm concerned that a) it will look out of place and b) that I don't know how it will work logistically since our friends are the kinds to save seats for those arriving later.
My original thought regarding ushers would be that they would be the ones to escort my fiancé's grandmothers and my stepmother to their seats before the profession started and let people know where the programs are if anyone asks. Now I'm trying to figure out the best approach- all thoughts are welcome!
ETA: our wedding will be in a hotel courtyard