This is the heart of the problem the French had, and why they did so badly. Without a large, long-service officer corps they instead decided to rely on a high level of planning at HQ, with orders followed exactly all the way down the line (which reduces their need to train the lower-level officers, meaning those slots can be filled by reservists). Combine with the fact that most orders were still sent by despatch riders and not even by telephone let alone radio, and you've got a toxic mix where it took the French Army three days to react to a situation. Unless they get very lucky, that means they're going to lose a war of movement with the Germans.Which is the problem concerning the "French professional army" suggestions on De Gaulle's model that gets passed around. In the Third Republic it is unacceptable. The left is convinced, and not entirely without reason, that a professional army will be used against workers and to suppress them. In 1914 the plan had been outright for the replacement of the army overall with a popular militia, and this had only been scuttled by the outbreak of the war. In 1928 the army had been entirely restricted into a small standing force that trained large reserve elements, short term reserve elements, minimizing the total amount of time that the general population would be serving and thus preventing them from being separated from the general population's values.
As for the rest of the French armed forces, they weren't bad at all - pretty well equipped for what they had to do, although there was a fair bit of defeatism particularly in the AdA. That's mostly a legacy of the interwar turf fights with the Army.
So as for what they can do, that splits into two streams:
- Speed of communication - that means the extensive use of radio and telephone to ensure that orders are disseminated much more rapidly. The irony is that being very heavily mechanised/motorised the French are inherently better suited to this than the Germans, but they never went in for it in the big way they should have.
- Better training for and more reliance on the more junior officers. This one is a complete political minefield - the professional officer corps advocated by De Gaulle is just impossible, but longer annual training (say officers spend an extra couple of weeks per year doing staff training and TEWTs?) might be possible.