UK Delivery Times

Just wondering why the difference. I have a listing with 2 other sellers on.

(FBM). Arrives between June 12-17. Want delivery by Wednesday, 10 June? Choose Two-Day Delivery at checkout.

(FBM-Mine) Arrives between Thu, Jun. 11 - Fri, Jun. 12. * Want delivery by Wednesday, 10 June? Order it in the next 0 hours and 28 minutes, and choose One-Day Delivery at checkout.

(FBA) * Want delivery by Thursday, 11 June? Order it in the next 11 hours and 27 minutes, and choose Standard Delivery at checkout.

On mine Amazon expect me to post the item the same day and deliver the next day, or lose the right toi offer Premium Shipping.

The other FBM shows same delivery day as me but with a slower service.

Amazon FBA seems very slow?