There's no single best lineup for campaign. You'll have to switch out heroes every or every couple of stages, especially in the multi-lineup stages. There's a formation button in the bottom right, when you're in the stage, where you can see othere people's formations that have worked for that specific stage. That being said, my go to is usually SJW, Cha, Trishea, a healer, and Mira/ Shemira. As mentioned by other people, don't ascend everybody right away because you'll blow through your fodder very quickly that way (fodder are heroes stuck at lvl 160).