Hi again
To answer quickly, the difference between these schools is simply the level of influence and reach they have. The better it is, the harder it is to get in the school's programmes. To give you an idea, you could visualize a pyramid, as there is fewer and fewer schools available the higher you go.
For pre-experience master programmes, this is how it goes in France :
- HEC is at the top. No contestant or competitor whatsoever. It is a top-tier school, which gives you the best opportunities a French school can, in France and over the world. It's also by far the hardest to get into.
- 2nd tier : these are top-level schools, which will give you good education and job opportunities. To cite a few : EMLyon, ESCP, ESSEC...
- 3rd tier : these are above-average schools, which are good enough to have a regional - sometimes national - reach. Examples : Grenoble EdM, Audencia, Kedge, EDHEC, Neoma, RSB...
- 4th tier : average schools. The value-for-money is not that high, and I wouldn't advise anyone to have them as their first choice. They have very local influence and won't push you very far on the job market. There as dozens of them all around France, in public and private institutions.
- 5th tier : below average schools. There are also dozens and dozens of them, aimed mainly at French students. Really not worth the trouble, except if the seal "I studied in France" is really worth it back at home.
Most of the 3rd tier schools and up have the three accreditations. Nonetheless, the opportunities they offer you are far and wide. The notion of quality of education as well is something that could be discussed. The general saying is that, the higher you go, the best education you recieve. Then again, some will argue that the biggest difference between the first three tiers of schools is the "brand" you purchase (which name to put on your CV, which will hopefully open you doors than others won't), not the lessons they give you.
In the end, I would like to stress again the language requirement. Please understand than in order to get a job in France, you will most of the time be asked to speak French at a business level (C1 level). An intermediate level most likely won't be enough. From there, only you know if you can meet this level during the course of your degree.
Anyway, I wish you the best for the pursuit of your studies !