I've always been fascinated by the historical context for our "Best Man" and "Maid-of-Honor."
Historically, the Best Man was literally the best swordsman you knew. It was his job to fend off guys who decided your wedding day was a good day to attack you while your back was turned and you were looking at the officiant. The Best Man would watch your back, and cut down anyone who made a run at you.
The Maid-of-Honor literally vouched for your honor as a virgin. She was a trusted family friend who would speak to your chastity.
In either case, you were literally choosing someone who would be your champion of sorts.
Twisting this for goblinoids, how about:
The groom's best man, or "best gob" must square off against the bride's "gob-of-honor" in a duel of goblinhood. Since everyone knows a female goblin is just as capable as a male, the terms of the duel are negotiable - from combat, to dog hunting, to who can eat the most rats in a 10-minute period.
The winning champion's newlywed-to-be then earns the right to set the terms of the marriage. I.E. whoever's side wins gets to the wear the pants in the relationship, with all the rights and privileges that come along with such a victory.
