They should stop doing the song - dance format. Instead just song - song. I'd rather have two singing performances from both teams and it's what they will actually do whenever they perform.
Anyway, Team A seems better but I think the emphasis on dance favors B right now. While A is doing more better music performances, I think B is winning primarily in dance and song selection, aka upbeat pop/dance music compared to A, which makes it more "fun" as a spectacle. When listening to just the performance without visuals, Bs performances have been lacking in the singing.