Nope. Not true.
The mercedes would need less cooling to the engine and electronics.
Also, the size of the intake does not dictate the flow resistance through the bodywork. The flow resistance through the bodywork is the real drag producer.
Anyway. My Pecking Order so Far.
1. Mercedes
. Gap
2. Ferrari
. Gap
3. Force India
4. Williams
5. RedBull
6. Toro Rosso
7. Mclaren
8. Haas
9. Sauber
10. Renualt
11. Marrusia