Don't nobody want 60 year old RDJ trying to negotiate for a Doom quest film. Let's finish out this phase 3 and 2020 we have the MCU with the the real mutants not some wack terrigen mist meta humans or talking raccoon and his team that no body would care about if Silver Surfer and Galactus were available to marvel....
Rocket Raccoon stand alone would do better than any film Fox has made. Guardians are most popular than X-Men and F4 combined too
these are facts if we're talking strictly film wise.
What are you basing this popularity on? Did Rocket Raccoon have an immensely popular kids television series? Or a film franchise since 2000? Or critically acclaimed comics that's launched careers of many artist and writers?