Here’s a playlist of Alliance War hits recording how I routinely one-shot about half of my attacks and score more than 300 points per war. All while using mostly a mix of maxed 2-star & 3-star heroes and sometimes unleveled or half leveled 4-star heroes. I cover how I select which defense teams to hit and compose mono-color teams for my attacks. The early videos also cover how to compose teams using unleveled feeder heroes.
If you have lower level alliance members who struggle with alliance wars, they should watch these videos.