The whole crimp vs solder vs both thing seems to ultimately be a religious debate that 99% of the time doesn't matter.
Why do I say that? Every source I've ever read/heard in the most demanding electrical applications (racing, NASA, etc.) says you don't solder crimped connectors using stranded wire. Many hobbyists and a heck of a lot of pros do it anyways and never have a problem. Conclusion? The vast majority of the time it probably doesn't matter, either works for people, do what you want. Though technically not best practice, most people don't use quality connectors and the proper crimping tools, so belt-and-suspenders soldering might be an improvement over a bad crimp.
My expertise: None. Just a ton of reading of things like NASA technical standards and from aviation/marine pros to learn how it's done where the costs of failure are highest. Otherwise, I'm just another guy on the internet. Not trying to claim anything I'm not, just passing along what I've learned.