The settings under this section answer the question: when will students be allowed to submit their assignments and assessments?
Note that the submissions and assessments can open on the same day. However, assessments cannot open before submissions (there would be nothing to assess).
If you enable the Switch to the next phase setting after the submissions deadline, then after the submission deadline, the workshop will automatically switch to the assessment phase. If you do not enable this setting, the teacher will have to manually advance the workshop to the assessment phase.
If you have the workshop automatically advanced to the assessment phase, you should also have the workshop automatically allocate assessments to ...