Wow there is some loaded ubisoft pr lingo being subconciously used there (develop a franchise huh? I remember that one. That was watchdogs.)
First off, you need a director/lead who knows when to say no, so your project doesnt spin its wheels and spiral out of control.
The most expensive parts of modern games is the ad budget, and cinematics and voice acting. A large amount of content can be made by a moderately small team. Monolith soft had a staff of a little over 120 something for creating the 400 square Kilometers of hand modeled real estate in XcX.
Dont develop a franchise. Make a game you would want to play, make the best you can, and put it out there, if people identify with it, they will buy it, and that success will give you clout to get someone to invest in your sequel, so you can make a bigger sequel with bells and whistles the first game didnt, and if thats a success, you might just have the beginning of a franchise on your hands.
The power was in our hands, instead of a marketing team telling us they are making a new franchise (without a single game in it) with an iconic character (that hasnt even been seen yet) oh, and you can already by one of 30 dlc options...
Or, at least thats how it used to work before AAA scorched the earth, cultivating an audience that wont even look at a game that doesnt have expensive vo, cutscenes, and overbearing marketing, pricing the mid tier out of the market.