France attacked 25 October 1939

Air Force was essential in 1939 - though there was three major Airforces - Luftwaffe, Armé de l'Air and RAF each with its perception of role and how to pursue Airwar.
Essentially the one AF of the three having a clear idea of what to do was the Luftwaffe - support the Army in operations. Thus during the French Campaign the LW did so and to do so had developed Fighter Aircraft, Medium range Bombers and Divebombers. Also a system for close Airsupport had been implemented (though it didn't always work 100% as the many pics of WWII showing German troops putting Nazi flags on the ground, vehicles and ships to avoid friendly fire) and it worked.

Yes, yes, yes - probably boring to most but I find it of great interest to the situation:

Difference in Armour doctrine:

French Tanks only had a three man crew with the Commander being also Gunner and Loader and the only man in the Turret.
German Tanks except the Pz. I and II had two to three men in the turret.
British Mk. A12 ”Mathilda” and Cruiser Tanks had a three man turret, the light Mk. VI a two man though the heavily armoured Mathilda A11 had a one man turret.

Germany – each Panzer Division would have at least 2 Infantry Battalions (2) though 6 had 4 Infantry Battalion and 2 had 3. Additionally 6 Divisions would have a Motorcycle Battalion equalling another Infantry Battalion giving each Panzer Division at least 3 Infantry Battalions (3), 3 would have 4 and 4 have 5.
The Panzer Divisions had usually 2 tank Regiments though some had 1 – the former Light Divisions. As an outcome of the Polish Campaign the 6 original Panzer Divisions got an extre Infantry Battalion while the former Light Divisions retained theirs, also the original 5 Motorcycle Battalions was cannibalized to make 3 more. With only a month to mount the next Campaign the Panzer Divisions would be slightly less strong in Infantry.
When the Germans undertook Barbarossa in 1941 the original Panzer Divisions had been stripped of 1 Panzer Panzer Regiment to form new Divisions AND the Motorized Infantry Divisions had been stripped of 1 of 3 Infantry Regiments to give each Panzer Division a full second.
These new Panzer Divisions – in a modern context Mechanized Divisions - did well during the rest of the War.
The Germans were on the right track in giving the Panzer Divisions more Infantry to make them more balanced and able to operate independently.
The Germans also fielded 4 Motorized Infantry Divisions in Poland each of 3 Regiments of 3 Battalions. These were then thinned down to 2 Regiments for France to add more infantry to the Panzer Divisions and set up the 11. Motorized Brigade and following Barbarossa was upgraded by having a Panzer Battalion added making them Light Panzer Divisions.
However with only a months interlude this change might not happen.
Several SS-Motorized Infantry Regiments had taken part in the Polish Campain making the Army able to field a Panzer Unit Kempf of one Panzer Regiment of 2 Battalions and a SS Infantry Regiment of 3 Battalions with 3 Artillery Battalions.
With little time to reorganize and implement experiences of Poland Campaign the Army may decide to use the Motorized SS to give the Panzer Divisions more Infantry.

French – fielding two types of Armoured Divisions the DLM (Division Legere Mechanisee/Light or Fast Mechanized Division - according to a French website) and the DCR (Division Cuirasse Reserve/Armoured Reserve Division).
The DLM would be the only ones to take part in this ATL as the DCRs hadn't been formed. Only a Heavy Tank Brigade had been reserved to build those DCRs from. The DCRs were to have no Reconnaisance Unit so would be ”blind” - some French argue that they were to have worked in close cooperation with an Infantry Corps not as Independent units.
The French also fielded 7 Motorized Infantry Divisions which would be allocated trucks and buses from a pool for Motorized movement – like the British Infantry of 1940 and the US during 1944-5.
The French also rebuild their Cavalry Divisions during the Phoney War from 3 Cavalry Divisions to 5 Light Motorized Cavalry Divisions which was VERY lightly armoured.

The two DLM Armoured Divisions (a third would be formed during the Phoney War) had a Tank Brigade of two Regiments (Battalions) – one Regiment of 48 modern fast Tanks Somua S 35 the other of slow Tanks but both heavily armoured.
A Brigade of an Infantry Regiment of 3 Motorized Battalions and an Armoured Reconnaisance Battalion. It also had an Artillery Regiment of 3 Battalions – 24 75mm Guns and 12 105mm Howitzers.
The Motorized Infantry Divisions was organized like foot Infantry with 3 Infantry Regiments and two Artillery Regiments of one of 3 Battalions 75mm Guns (36) and one of 2 Battalions 105mm Howitzers (24).
These units according to the Germans worked well in the Battle of Hannut 12-14 May 1940 in Belgium putting a breake on the advance of 3 and 4 Panzer Divisions.

The British 1 Armoured Division was prior to shipping to France built of three Tank Brigades, one Heavy, two light and a Support Brigade of 2 Mechanized Infantry Battalions and 2 Artillery Regiments of 16 18pdr Guns each. During the October the Divisional Artillery was sent to BEF in France. During November one of the light Tank Brigades was used to form 2. Armoured Division.
No matter when the Division is sent to France it will be lacking Artillery.

The Army 1 Tank Brigade which was sent to France as part of BEF had 2 Tank Regiments one of Light Tanks and Heavy Tanks with only Machineguns and one of Heavy Tanks. Of its 112 Tanks only 23 Heavy was real gunarmed though those and 77 Heavy Tanks with only Machineguns were heavily armoured. It was a pure Tank formation no Infantry no Artillery.

Two Armoured Reconnaisance Brigades were also sent to France each of 56 Light Tanks and about 300 Mechanized Infantry.
Essentially would be a real Armoured Force if it had real Tanks like Cruiser's and Artillery though of actual Battalion size.

It won't be but even more so the Medium Bombers being unanble to operate as these were much more numerous than Stuka's and carrying a much heavier payload. Also than the WAllied Medium Bombers.

Forgot these -

British:
2pdr./40mm standard Tank gun and Anti-Tank gun.
Penetration 34mm at 1371m: all.

More on Anti-Tank Guns:

The important thing her is that the French and British units won't be in need of calling up AA-guns (the Vickers 75mm could double as an AT-Gun) do defeat German armour the needed AT-Guns is already deployed to Army units.

The Germans as OTL will have to rely on the 88's which wasn't part of the Divisional AA-guns nor the Corps AA-guns. Being Nazi-Germany things were of course complicated.
As far as I can find the Luftwaffe by 031039 was forming new 2 FLAK-Corps that was to support the Panzer Divisions of Army Groups A and B during the French Campaign. The German Army must have realized that more AA would be needed in the West than what had been around in Poland.
The Battalions were of three types – Light of 3 Bty. 20mm, Mixed of 3 Heavy Bty. 88mm and 2 Bty. 20mm, Heavy of 3 Bty. 88mm. All units Motorized.

The Commanders of the two Corps had been appointed 031039 with one Regiment formed 081039, one 251039, two 281039 and two only mentioned forming during October 39 – Commander not named. These 6 Regiments would total 1 Heavy Battalion, 17 Mixed and 7 Light Battalions. The Light Battalions would have no real impact on Allied Tank losses.
Of course units might be despatched to be in place by 251039 and the issue of missing Regimental Commander given a temporary solution but actually some units due to inter-service rivalry might just not show up! Göring would be jealously guarding his Empire of Air.

Besides being necessary to kill WAllied Tanks the FLAK guns made effective objective defences of bridges against WAllied air attack.