latest update from the ECB.. up to 6 can now net
Small group cricket activity, training or fitness in groups of no more than six (6), is permitted, keeping two (2) metres apart at all times.
Cricket coaches, can now undertake small group sessions of up to six (6) people including the coach (1:5)
and they must comply with ECB safeguarding policies (as well as being able to conduct one-to-one coaching).
https://www.ecb.co.uk/news/1676621/updated-guidance-for-return-to-activity-in-a-club-setting