It doesn't need a large ship. It can be a dedicated smaller team but one fully equipped with more resources (servers, a marketing department) compared to the start up.

Just to take a decision on copying the idea, creating the team, how many people, degrees of independance, internal politic on who is on charge of tha team.... Only with that it is going to take at least 6 months in a big company. If not a year... then when they have created the product, all the departments will want to have a part of the pie. So te dance begins again.

OK, a larger ship, which is the topic at hand. More resources means more complexity.

Just last night my girlfriend was up for a couple hours late on a Saturday night PM'ing a bugfix for a missing ellipsis in her (very large and technologically famous) company's website's "...More Info" link. It took 10 hours to get her off the hook, and it's still not fixed.