Yes, because the film companies need to try new couples in movies. In addition, new couples could look more fresh the film, be more interesting to people who likes movies a lot. This could be an interesting comedian couple these days and both actresses have a long successful career in Hollywood.
They seems to have wonderful chemistry with each other in the commercials for the movies and in some interviews I have seen of them so I don't see why they can't be the next comedy duo. A lot of people thought the cast of Bridesmaids couldn't pull it of but it ended up being a hit! I'm all for more female-driven comedy and action-comedy movies.
Basically anything Witherspoon is in is a comedy. She can turn most situations she is in into something funny.I think Witherspoon and Vergara together is going to make for an absolute hilarious movie. Hot Pursuit will probably be the best comedy of the year. I can see the two of them making more comedies together.
They don't have great chemistry, which really is what makes duos work. Female comedy duos don't seem to be as funny as male comedy duos. I don't know why this is so. There are a lot of funny females, but the genre just seems odd for two women. So I don't think this will go very far.