Placement of spouse of relative
I would be more inclined to believe the details if the two trees were common ancestor couple on top followed five columns on the second line or row by [spouse] of (son or daughter) [relationship] (son or daughter) with [spouse] on the next line or row. The second line or row son or daughter equates to one of four sibling possibilities. 1 brother-brother, 2 sister-sister, 3 brother-sister, 4 sister-brother. Subsequent generations repeated similarly with their descendants to the current generation showing the relationship on each line or row in the center column.
1