Despite the presence of some German 20 & 28cm long range guns the French artillery had overall superiority to to German for this sort of attritional 'assualt' battle. The 80cm guns were not available until late 1941 and they were extremely vulnerable to air attack. While the Germans had some sucess in keeping their heavy artillery protected from the Soviet army in 1941-43 its likely the much more sophisticated French artillery would have been able to counter them.

The Biggest Gun - Gustav

A realtively static battle in the Fortress zone was the sort of fight the French air force had prepared for. The Luftwaffe had some important advantages in command & control, and liasion with ground units. But these are much less marked where the Germans fight by the traditional rules, that is a positional battle through the fortress zone. In that case the French air force would be better able to cope with the tasks of target planning, local air superiority, and execution of air strikes. Historically the Germans suffered appoximatly 1000 aircraft permanetly lost during May & June 1940. A battle fought as the French trained for is likely to place German aircraft losses at a much higher level. Particularly in the case of Me109 fighters.

All this of course assumes the Wehrmacht or Luftwaffe does not develop some combination that allows a rapid advance through the fortresses. Like they did through the Meuse River defense historically. If they can somehow create a wide corridor through the fortress zone in just a few days then the slow French Command & Control will be overwhelmed as it was historically. This still may not guarantee stratigic sucess, but the Germans would be 'through the Maginot Line'.