No. It would be awful. Lana's wispy highs would be completely over shadowed by Gaga's power and her pitchy lows would be overwhelmed by Gaga's precision.
Seriously. Just. No.
MM and Lana's voice would not go together at all. You guys need to think of how their voices match and the tones of their voices. Gaga and Lana both havs a specific quality in their voice thay would not go well together. same with Marina Diamindis.. Her and Gaga MIGHT go good together.. but its doubtful