ID please

My friend has this plant one is in good condition and we are not sure what’s wrong with the other, any help please

 

it’s not in a pot it’s just in the border

 

Two plants growing in different positions perhaps.
Are they the same variety? They do look different.

Maybe one catches more direct sunlight for longer or more wind.
The dodgy one could have pest problems, scale insect for instance.

 

I wondered if it looked like a pest problem, should she cut the dead branches right back?

 

If they are dead then yes, I would cut them back.

But it would be good to find out what the problem is, so as to avoid it next year.