I see nobody answered your question about C. argiolus.

The name was actually given to a Eurasian insect. However, for many years it was thought that ours were all the same variable species with a wide range across two continents. However, now it is thought by many people that none our "Azures" are the same as any of those found in Eurasia, and the name C. argiolus has been dropped for all of ours. Another development is that the idea of all of ours being the same species has changed. It is now understood that we have some populations that are definitely distinct species with different coloration and other characteristics that make them recognizable, and that do not interbreed with one another. There are also lots of populations that use different food plants, or seem to appear at different seasons, but that are not easy to draw lines between. Right now seems to be a phase of learning and naming, and many new names are being given to such populations as if they are really new species. Some likely are, and many likely are not. There has been much study, but needs to be much much more before these Blues are fully understood. To add to the confusion, they are variable in coloring and patterning within populations, and different "broods" of the same population may look quite different (probably the coloring and pattern is affected by things like day length, temperature, and even humidity). So, right now, to sort them out based on photographs alone, is very difficult. Especially since there are varied and conflicting opinions on what is going on. [Personally, I think there are few very adaptable and highly varied species - non many. I also have no problem with the idea that some of ours really could be the same as some of the Eurasian species.]