Pleached trees (No replies)

Hi - I bought a new build property and it came with 5 pleached trees along the rear fence. I assume to act as a privacy screen. There are two problems: 1) there are not enough of them, they are planted at 12 ft intervals, meaning they will never create a screen 2) they are deciduous which I also don’t understand when they are planted for privacy.
I thought about removing the trees (and re-planting on the sides) but they are now 2 years old so quite established and would also be expensive. Therefore I was thinking of just buying 4 additional trees to plant in between so will eventually form a screen.
I am thinking about buying photinia red robins as it will provide screening all year round. However, I can’t decide whether the mix of evergreen red robin with the green deciduous will just look silly/rubbish or if it could be construed as a well-conceived contrast! Any views gratefully received!