Its a really nice change from the typical "I survive alone" of zombie- text games to managing a group of people with different skills.
The interesting part is that there is no explicity, neither about the skills of the characters nor about the skills that the tasks require. That means you need to play around and try different characters in different situations till you figure it out.
Sydney is stupidly OP and I wouldn´t say Vivicia is useless, as she has some events where she actually manages the task... in her own way.