I think some of you guys are taking this show too seriously. It is not a documentary, it is basically a soap opera based in the 60's. I take the points about the same crew working together on all routes at all times is not realistic, but it is a PLAY. There would be little continuity if the crews changed every week even though that would be more realistic.
As in any soap, the happenings are telescoped into a short period and perhaps more of them occur than in real life, such is the way of a TV series. Those of you in the UK will know the British soap, "Emmerdale" ostensibly about a small village in Yorkshire. There have been more people killed in one way or another in that small village than in many a large city.
Just sit back and enjoy it for what it is a bit of light entertainment.