If you are allying France. 1. Research paratroopers. (Add only "Recon" as support company to increase movement speed to capture victory points quicker)
Wait for Germany to attack France
Technically you should be having more fighter planes than he does, so simply have air superiority in Western Germany/Northern France.
Prepare a naval invasion to a certain region (not a port) (he will have divisions guarding that).
When he pushes in France, parachute in Maginot, leave few divisions in Maginot, with the rest -> push Germany (He won't be able to comeback through your guarded Maginot line while you push into Germany)
At that stage he should start diverting some divisions from the coast to deal with paratroopers. (Check the coasts with patrolling with a ship)
Then go for a naval invasion.
By then, you should be able to capitulate him, considering Raj and Canada will send you divisions to help you.
I do that in most multiplayer games, most players go into panic mode, and think that the threat are the paratroopers when in reality the threat is embarking on their land.
Although as you mentioned that he played Hearts of Iron since the release of the 3. He might see through that but good luck.
(*I advise you to NOT listen to others saying you should just hold, you will fall behind him more and more, it will reach the stage where you will be behind in fighters (because of German production capabilities))
If you want to win, it has to be early, at best you will face a stalemate, or at worst - you will lose.