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