I thought so too, but I was admonished by
@Darreno and a moderator removed my post.
FYI
@Mr Miserable I found my VIN today, I'm in Ireland, and EDD moved earlier to 9 Aug-23 Aug.
If both MORNING CHORUS & GLOVIS SUMMIT head to Zeebrugge and both arrive around 17/18 Aug, then the vehicles could be on the scheduled
CLdN RORO on Thu 18th or Friday 19th to Dublin arriving early morning on Sat 20th or Sun 21st - right at the end of the EDD window.
So your hypothesis that there may be another ship arriving Zeebrugge sooner is possible. Happy hunting, and thank you for sharing your insights here with us.