Why always Tangmere?

[furnessvale]

You're missing the point gentlemen. The assumption should be that there won't be these operating incidents. A more valid comparison would be between their incidents per route mile or service operated, compared to other operators doing similar work.
Re the Scottish services, don't forget that they are operating over what is effectively a low speed, isolated single line.

I'd have thought a more valid comparison would be with ALL other trains on the main line.

If charters are demonstrably less safe the issue needs addressing.