The number of authors doesn't seem unusual there, and a high number of authors doesn't have to indicate anything problematic. There are many valid reasons why

The number of authors doesn't seem unusual there, and a high number of authors doesn't have to indicate anything problematic. There are many valid reasons why author lists can get rather large on scientific papers. Anything that is even a bit interdisciplinary will usually multiply the authors because you need collaborators with the right expertise and can't do everything yourself.