When you use SR, the cost will significantly increase.
Total team's cost = (Sum(Card cost^2)) x AreaCost
Asume you have a team with 4UC 4Max -
Spear Tsukasa lazuline, Yoki Berufu, Fam Benihomura, and Rukia blade of jade compare with a team with 1 SR 4Max -
Sandra soldiers prisoner.
Member damage = skl + physic damage
Team 1 's damage = 18009 + 20030 + 18137 + 17395 = 73571
Team 2 's damage = 35049
Team 1 's cost = AreaCost x (12^2 + 12^2 + 12^2 + 12^2) = AreaCost x 576
Team 2 's cost = AreaCost x (46^2) = AreaCost x 2116
Team 1 's damage is double but cost is 4 times smaller.
There 's only 1 problem is your team don't have enough damage to clear map with just UC.