Dent Advice Please

I need some dents taken out of my wheelarch panel. I know the panel needs to come off and be repaired and repainted. But have been told the whole side of the car needs to be repainted? There is no damage to the door just the one panel. Seems very strange to me, he said "its to do with matching up the paint"

Thanks for the answer
Have to admit im still puzzled.
With my old Crossfire i had a mobile bloke come down repair the wheel arch and repaint the damaged area, he done it in 3 hours and you could not tell it had been done. I had the car another 3 years and you could not tell it had been done, as the garage who brought the car never mentioned it.
Last year i had a smack, car driving very fast never saw me pulling out, whole front wheel arch panel had to be taken off and repaired again the garage never even knew it had been done.
I can understand painting a bit of the door, but the whole side? seems very strange, need to find out a bit more about this

What about PDR? as their is no breakage in the paint, have heard it can work and save you a packet?