Yes, one of the big differences between the old halon system we got rid of many years ago, and the newer argonite systems, is that the argonite requires many more gas cylinders, because (as you say) argonite works by getting rid of oxygen, instead of chemically suppressing combustion. The small machine room in our office building was refitted about 8 years ago with argonite fire suppression, and they had to add pressure release vents between the machine room and the outside so that there was somewhere for a room full of air to be displaced to.
AIUI being in a room during a halon dump is unpleasant but not too dangerous, but you really don’t want to be in there when the argonite release happens!