I think the point is that proper flux and temperature controlled iron is arguably more important than technique. I often see people talk about drag soldering on this forum like its some unique technique but with adequate flux, a decent (temp controlled with a smallish tip) iron it can actually be quite hard to make solder bridges. Regardless of whether you "drag", or touch each pin one at a time with a tiny bit of solder on your iron, doesn't make a difference, let surface tension and flux do the work. So yes, experience helps with knowing what tip to use, and what temperature, but there isn't anything magical or even skilled about "drag soldering".
For connectors, you can of course use hot air, I worry about the plastic parts and try to shield them as best as possible. The connectors are designed to withstand the soldering profile of an oven, but with manual hot air, it can be quite easy to melt the plastic of the connectors given that their temperature is a function of hot air temp, air flow, distance from nozzle to board etc.. So if you can get your iron in there - I'd do it that way.