I hunted with 4 people before and we split into 2 groups Me and my younger bro and my dad & older bro went another way. Dad and I ended up calling a hot bird back and forth for about 45 mins before I figured out what was going on. Then I shut up and not long after that I heard BOOM!!!, my younger bro and I sat tight and looked the direction of the blast and here comes a different gobbler running...The gobbler ran right to us and met some no.5's right in the beak. So as a family we ended up taking home two birds.
I'd say split into two groups, but plan it out because one group may have to shut up to help the other group.
I don't usually see too many "groups" of gobblers in the spring time so I wouldn't concern yourself with that too much. Even if a bird is in an adjoining timber, it can be persuaded if you work your calls right. So your total of 80 acres for 4 people looks better if you think that way.