Finally done, here is how I completed all of 2nd stages:
?-7 - 2 teams of 550 on top and 3 teams of 500 on bottom
?-8 - 2 teams of 500 on top and 2 teams of 550 on middle and 1 team 500 on bottom
?-9 - 1 team of 600 on left and 2 team of 400 on middle and 2 team of 400 on right
?-10 - 4 team of 500 on left and 1 team of 600 on right *
?-11 - 2 team of 600 on top left and two teams of 500 on top right and 1 team of 550 on bottom
?-12 - 3 team of 500 on left and 1 team of 400 on middle and 1 team of 600 on right
Using this method I had a very easy time with the 80 stamina stages. Got lucky with the RNG, especially with the first phase being RNG hell for me, but I got through the 2nd phase pretty quickly. Luck is involved like always, but this is a great setup.
PeroPero: Zerana (879179) 55 out of 62 PeroFriends Osawari Island: CR20OG4XY3FGUTSJJ8599 (10 out of 10. Ty everyone ♥)