Short Answer: Yes, it is possible to obtain all of these DLC exclusive Pokemon, and any others you may desire, through trading.
Long Answer: This can technically be done through in-game trading functions, but I recommend trading through Pokemon Home on your phone to refine your search and vastly increase your chances of actually obtaining these Pokemon. Since Raging Bolt, Gouging Fire, and Iron Crown (plus Iron Boulder) are only one per save data and require significant time/work to obtain in-game, they might be difficult to obtain through a trade since people will be less willing to give them up, at least without bargaining chips like rare shiny Pokemon. The Loyal 3 are similar in only having one per save data, though they are much less work to obtain, so could be a bit easier to obtain, but no guarantee. As for Archaludon, that is a simple evolution of Duraludon, obtained through using a Metal Allow item on it. Since they are unlimited, and not terribly difficult to obtain, trading for one of these should be significantly easier.
Hope that helps!
