Can multiple resources be assigned to one package?

... and can several teams or skills also be assigned to one package?

Yes.

In principle, Can Do has no limits. You can assign an unlimited number of people, departments, skills and departments in combination with skills.

In Can Do, these resources can not only be assigned to packages, but also to phases, projects or portfolios.

Only milestones cannot be booked as resources because they are not "work" but events.