People forget that Barcelona is high-downforce circuit and start predicting according to that. It is RBs circuit and if they are closer to Ferrari then expect Ferrari to be ahead of them on other circuits. Similarly Barcelona is not Force India's circuit they don't design their aero according to this circuit. Haas will perform good here as does Renault & Mclaren, come Aus GP we'll see some predictions getting completely wrong.
Here is my prediction, for Aus GP :
1). Mercs
2). Ferrari
3). RB
4). Renault/Haas
6). Force India/Mclaren
. Williams
9). Torro Rosso
10). Sauber
Remember Renault, Mclaren & FI are accepted to make improvements as season progresses. Haas does look like last years Ferrari but thats all they can offer at the start of the season, as it passes they'll fade away at back of the grid.
Pecking order till Spainese GP :
1) Merc
2) RB
3) SF
4) SFI/Renault
6) Mclaren
7) Haas
Williams
9) TR
10) Sauber