TWD: All-Stars Official Forum (The Walking Dead: All-Stars)

For me, the best way is to deploy your best team, to secure ate least the bronze rewards. After that, work your way to assemble the best team meeting the criteria of the other reward tiers. In my case, Abraham was used in all of the stages, basically deployed the 4 toons of a specific type and abe. Just keep trying, rotate the team and give that rgn a chance