You guys are clearly not realizing this point -- I can't believe this was the first time it's mentioned. His style/outerwear/trickery reminded me almost exactly of these two. Losing two big names in the "steeze" game needs to be compensated for their movie to still be marketable to the same crowd it once was, and Sig is by far and away the right choice to fill that void.
Maybe not the "best" choice, but definitely the smartest choice by Berman and his crew, no questions asked.