"Sacha" wrote

A mixed hedge over a large area can look good if chosen well. Over a
small
area it can easily look a mess if intended to be a hedge, rather than
individual plants allowed to follow their own growth pattern. The OP does
not, I think have a large area on which he wants to plant a hedge.

Not sure what you mean by a large "area".
The hedge I describe is maintained at about 600mm (2') deep, 1200mm (4')
high and extends for a length of about 20m.
I guess in this case the length is irrelevant, but, apart from the photinia
I mentioned, the other varieties seem to cohabit OK in this layout.

Phil