Ok, so this is the airport that I was designing (work in progress) where I noticed the issue:
See how the outer terminals on the Eastern block are so far away for the service vehicles? Funnily enough, the South East corner is where I have the most space in the terminal to handle large gates.
Agreed, the baggage handling, depots, etc should probably be 1 set North of each terminal block for optimum reach, but assuming that I only had resources for 1 centralised hub, I would have no choice except to put it in the centre.
Observe below:
How having the Eastern terminal connected by an Overbridge allows faster vehicle movement by going through where ther terminal was and does not hinder passenger movement.