Mezumin before the end of a simcha

3 people want to leave early from a wedding/ simcha
Apparently, everyone who waits till the end of a simcha can bench together as one group…even though they are all sitting at separate tables in the hall
What if 3 individuals sitiing at 3 adjacent tables want to leave early.
Can they make a mezumin
a) and stay at their individual tables or
b) 2 of them have to move to the third table so that they are all sitting “together”