I am afraid that it is not possible to avoid the overlap.
It is worst with 2 fivesomes, as you can not avoid some pairs playing together 4 times while others only play together twice.
(3 6 1 2 10) (7 9 4 5 8)
(10 1 3 9 7) (5 4 2 8 6)
(7 8 10 1 4) (2 3 5 6 9)
(9 7 8 3 2) (1 10 6 4 5)
(6 5 7 1 9) (10 4 3 8 2)
(8 2 6 7 1) (4 5 9 10 3)
Probem 2 is slightly better. In this schedule,
(11 6 5 8)
(2 4 1 10)
(3 9 7 )
(2 10 9 6)
(7 1 5 3)
(4 11 8 )
(5 11 2 9)
(1 3 8 10)
(7 6 4 )
(4 1 9 5)
(8 7 6 2)
(10 3 11 )
(3 8 4 2)
(10 5 7 11)
(9 6 1 )
(6 3 4 5)
(7 8 10 9)
(2 11 1 )
most pairs play together once or twice, however 5&11 play together 3 times.
