Are your dates correct, normally a particulars of claim must be served within 14 days of the service of claim - 1 June. Check with the court.
Generally to acknowledge service file a defence the position is as follows:
The defendant that acknowledged service late, 15 days after service of claim but you may not have served particulars in time. If the court allow this the the defendant has 28 days from 18 may to file a defence, that is today.
The time period runs from 6 June.
The other two defendants have 14 days after the service of the particulars of claim to file a defence or acknowledge service. If they acknowledge service this period for filing a defence is extended to 28 days after service if the particulars of claim. So 20 June and 30 June respectively.
You should speak to the court regarding the dates. They are generally helpful to lay people who are not familiar with court process.
I hope this helps.
The important issue is speaking to the court about the date the particulars of claim was served. You may need retrospective permission to serve out if time.
I didn't understand your question - do you mean the defense will be in the form of a witness statement? The defence and witness statement ate separate documents