I suggest you ask to see the department's policy and procedure manual. There should be one in the dept. ...it is required in order for them to be accredited. Within the manual the issue you're asking about should be addressed...how many present for a procedure. There should also be a job description for each person working during the procedure, the credentials required, etc. Hopefully you'll find policy and procedure support for this issue and can take it to management...they are setting themselves up for failure ~ at the expense of the patient's safety .