2000+ pvp scores

Eec411

Can someone tell me how a person can score over 2000 points in pvp with 2 championed non-boosted 4* as their highest level characters?

I've seen absurd scores, but most of the time I see rosters with often multiple championed 5*s. My roster has 13 championed 4*s at the top, and yet I can sometimes barely crack 1000 points. The times I have a boosted 4* I can maybe hit 1300, but I still get constantly attacked post shield. Are these people just spending 100s of hp on shields to do this?

I'm baffled