My experience with PC motherboards in regard to your question is to only use a soldering iron where a hot air gun is just not practical. The power surface mount FETs that are numerous and have large thermally efficient track/pads are the most difficult component to remove without damaging the PCB. Hot air and kaptan tape to protect close by components is essential. I have repaired hundreds of PC system boards. Where possible cut the component body off of the component legs before attempting to remove the through hole pins. Electrolytic capacitors will readily pull off of their legs by leaning them sideways for leverage then pulling to remove the can completely, meaning only the plated through hole need be heated with hot air, and rather than use a desolder tool or solder sucker as we call them which can easily damage tracking, using a very narrow nozzle on the hot air rework gun to melt the solder holding the pin in place while gently extracting the pin with snipe nose pliers and then keeping the solder in the plated through hole hot, blow air through the hole with a quick dab of the nozzle, perpendicular to the PCB will result in a good clean plated through hole with the least amount of damage possible.