Not necessarily. The best rainmeister has always been Schumacher, who excels in the wet. I remember a coupla seasons ago, at a very wet Spa, Alonso's car was in the barrier - as were several others - while Schumacher just glided past without a care in the world !!
Aerodynamics are important, of course, but if the tyres aren't performing then it's like driving on ice. And this year there have been lots of questions about the quality of the Pirelli compounds, from their slicks all the way through to full wets. Both drivers and teams have complained about them. Can only wait and see what the FIA have to say about them !!
I've not seen any of the early practice runs for Monza, so can't comment, I'll wait and see what happens this weekend. But it's a great circuit, very fast, and I like driving it, though it can also be a right PITA sometimes !!