But how unreasonable is that? Seems like a fairly obvious thing to do, if there's disruption at one point that means some staff can't be where they should be then try running the service anyway, what on earth is wrong with that?
Definitions can be put around what 'disruption' means to ensure that everyone plays with a straight bat
But they won't play with a straight bat. There is already an "except during disruption" clause about drivers driving 12 coach trains which surprise surprise Southern have ripped up and ignored. That is why they are so keen to retain it now - so they can rip it up once the agreement is in place. Again, if it was all about minimising disruption, just have the guard and driver work together all day then the problem is solved.