Heavily depends on the nature of the work in question and size of team. Larger the team, and more foreign the domain the more time is needed to coordinate work.
Fix your management and you'll be able to hire part time easily.
It depends more on the personalities, values and organization of the workplace and the team — for any size, if more than 20% of people involved need to spend more than 2 hrs/week in meetings — it is an organizational/ops issue, not an inherent feature of the work.
> more foreign the domain the more time is needed to coordinate work
More foreign to who? If it is foreign to individual team members, then it is a problem of insufficient onboarding/training material and process, poor documentation, or under-qualified hire.