Option 1: individual essays. Students each write their own separate essays, drawing on information from and activities of the group.
Option 2: combined essays. Two or three students (no more) can, by mutual agreement, submit a single essay. The word limit is the same. Joint authors should say how marks are to be allocated (equally or some specified non-equal manner).
You should submit a full-length draft. I will give you detailed comments on cassette tape. You then make revisions. The final revised essay will be marked by someone else.