I've always thought it best to guide the PC generation, along the lines of the game you want.
A lot of groups just have players generate "Whatever" and then try to make it fit.
So you end up with a witch type and a pirate type and a paladin and a necromancer.
Then it's expected to see these people on an adventure.
If the adventure is written, you usually can get an idea of what will fit and what won't.
A large group especially, needs a guiding vision as to are they:
A band of mercenaries in a war-ravaged world?
Freedom fighters overthrowing the repressive government?
A noble, and his / her retainers, clearing the land around the stronghold?