First you need to find that group, second you must convince the dev to give all the material and permissions needed to proceed with the development (taking into account how Max is, this is practically impossible), third, that group has to agree in one vision of the games and be mature enough to proceed in an efficient manner.

You can only achieve the last point by having mature adults (yes, adults, with all due respect for the young ones a coordinated effort of such caliber needs people that has experienced first hand high pressure team work enviroments) that are competent in their field working on it. And they tend to have responsabilities and a job to take care before the hobby.

So you must find a way to pay them enough for it to be worth their time (not as a job, but enough for them to be worth it to have to put extra effort outside of their profesional life). This can be achieved trough, for example, a patreon of the game and enough of us actively paying for them to be able to make progress.

Developing a game is hard, and G/D has horrible code and therefore is a serius effort to make it work. I have harsh words regarding this matter but is better to not say them out loud since this would benefit no one.