I'm just offering some feedback as a person who gets a lot of assistance from the TEX.SE.
However, based on the content of the answers, Gonzalo Medina's answer to the [closed] duplicate is much better. In it, he explains the difference between putting two figures next to each other and two subfigures next to each other.
Strictly speaking, this doesn't answer the question any better than the answers to the original, since it just provides superfluous information. But for many use cases, this information will be very helpful.
My problem was I was trying to stack three vertical subfigures side by side with another set of figures. The combination of minipages and subfloats befuddled me, until I say Gonzalo's explanation of the two different types and saw the differences between the two code snippets he put in. This allowed me to figure out what each latex command was doing and solve my problem within a few minutes.
In any case, I would appeal that the best single answer to any of the "Two figures" questions on the site is sitting on a closed question, and perhaps it would be better if the questions were merged, a la this discussion here.