Beware he doesn't want to just fill the dents with body putty.
I'd be for fixing the dents if the end result will fit the future use better and it was done in a way that was considered permanent. Pulling would be the best I think but I certainly don't know if this can be pulled. If you do a lot of cutting and welding new material on it gets dangerous, IMHO.
The way dents are repaired on older cars is to bang the metal out to the original shape as close as possible. This is a wrinkle sort of finish and then this is smoothed with a limited amount of body filler. If I just had to have the original shape I think this would be better than welding new metal.
I'm not a welder tho, maybe one of them knows better than me.