DfE guidance has been updated again (yesterday), to clarify:
"Primary pupils do not and have not needed to be kept apart in the classroom, and we are encouraging primary heads to use the capacity they have and the flexibility we have given them to bring more groups of children back into school, if they can work within the protective measures’."
Many schools got this wrong. So many that the finger can only be pointed at the lack of clarity in the original DfE guidance.
SLT's around the country are tired. This term has probably been their toughest ever. But staff in education, governors, parents all need to come together now to offer the capacity that they're able to as quickly and safely as they can.