There is no legal requirement in the UK to carry any particular type of chart.
You need to carry information suitable for the flight. I am sure somebody will dig out the ANO reference for me
All CAA maps are crap. They never bear any relationship to the bit of land I am flying over.
I think that's true for all aviation charts to a degree. The ground features can be pretty ambiguous, but tht is the nature of map reading. The skill (for whose who don't use a GPS) lies in picking obscure features which are unique within a wide area.