You can assign responsibilities like this:

Door post, inner post, guide post, automobile post

A B C DE

B C D EA

C D E AB

400 BC

BBC CD

A B C DE

B C D EA

C D E AB

400 BC

Analysis:

That's it. Shift changes every hour. Because of the special location of the garage, two people need to be on duty, so when scheduling, everyone works in the garage for two hours. On average, it is fair, and everyone is the same.

You can arrange the next day like this:

B C D EA

C D E AB

400 BC

BBC CD

A B C DE

B C D EA

C D E AB

400 BC

BBC CD

And so on. There should be no objection, because every five days is a cycle, which is fair.