Hey, thanks for reporting this. There seems to be an issue with the event requirements which makes it look like the event can be attempted with 3 Bounty Hunter ships whereas all 4 of them are required. We've flagged this as a bug now. Apologies for the inconvenience.
This thread was added on July 04, 2019, with posts from EA_HighCommand.
Original Post
https://i.imgur.com/3cPdcQH.jpg