"Rust Question" YOUR INPUT NEEDED!!!

[gmc1969custom]

My GMC is in the paint and body shop as we speak awaiting it's makeover and here is my situation. I have a small amount of rust on the passenger side rocker panel as well as a little rust on the bottom of my passenger front fender, my paint and body guy says he thinks it is best if he just cuts out the rust, then uses dyno-glass and then bondo, primer and paint. I initially thought it would be better to just replace the rocker panel, and for the fender cut the bad spot out and weld new sheetmetal back in its place, but since the rust is pretty minor he said if this was his truck this is the way he would do it. What do you guys think? FYI this is a veteran paint and body guy and me and my family have used him often in the past and have had good experiences with him, I just want everyones input since I know this is a common problem with our trucks and you guys are the best ones to ask!! Thanks in advance.