I'm looking into two possible sets of distant grandparents to my children. Comparing them from Gedmatch, Ancestry and FTDNA. I've compared two matches and found a common set of grandparents as well as another set and found a common set of grandparents all from the same tiny area in Sweden (even close farms). Trying to work down from there. As each has 7-10 children it seems. When looking at Gedmatch two of the 4 cousins I'm looking into are listed (one from each set if that makes sense). He matches 4 people. Out of those 4 they each match with one of the other 4. Anyways Gedmatch has a Gen suggestion of 4.0 for one and 4.2 for the other cousin I'm looking at. This may be a dumb question but does that suggest they share a ancestor 4 generations back (including them)?
When I look at the 4.2 the common ancestor I see (shared with another match) shares a great great great grandparent. Also possibly the great great but I'm not certain. These great great great grandparents I talk about had two children and I'm trying to figure when my children's decended from.

Anyways can someone explain the generation suggestion of 4.2? Or any input.