The Scrum Team members have courage to do the right thing and work on challenging problems. The Scrum Team agree to be open (to speak and listen) about all the work and the challenges with performing the work.
Scrum Team members respect each other's skills, experience, and opinions.

In self-organized teams creativity thrives, conflicts can be resolved, and new possibilities are explored.

Product Backlog items should be clear enough and have enough information for the Product Owner and Development to understand the work that needs to be done and to create a forecast of Product Backlog items to implement the Sprint Goal. Nothing stops the flow of Sprints, for example, we do not delay the Sprint because the items are not ready. In such cases, the "unready" items would be selected for the Sprint anyway and refined during the Sprint.
In the case that the Product Backlog items are not clear enough, the Development Team forecasts the most likely Product Backlog items to meet the goal and create a Sprint Backlog based on a likely initial design and plan. Once the time-box for the Sprint Planning meeting is over, start the Sprint and continue to analyze, decompose, and create additional functionality during the Sprint. At the end of the Sprint, the Scrum Team can discuss in the upcoming Sprint Retrospective why this happened and what changes will make it less likely to recur.

The productivity of the original Scrum Team would likely decrease as they would need to take time to assist and support the new Scrum Teams in order for them to perform optimally.

The ones that are closest to the work are the best ones to understand and explain what the work is and what the needs of the users and product are.