Most modern weddings (in the UK) wouldn't allow time for a 5x4 shot unless grabbed hand held like Whiteymorange suggests. The Pro covering the wedding dictates where and when people are, and has a hard enough job. I've been on both sides so can say if you want that shot you have to be ready to shoot just before or after the Pro and literally seconds The B&G + family & guest will only really do as he/she asks unless they already know you well.

My Grand-parents wedding was large format, 100 years ago this year, shot on 12x10 and contact printed, (I have THE print) and earlier shots of my grandmother & bridesmaids (sisters). The wedding shot is all the guests, surrounding the families, then both sets of Parent, and finally Best man, Bridesmaids with my Grand-parents. The whole scene was set up and planned before they & guests returned to the farm, they just got into position.

LF and weddings unless hand-held need planning.