Turn 1: Transfer 1 corps, 1 mech, 2 armor and entire Luftwaffe from the east.
Turn 2:

This image shows the start location of the units at turn 2. The key is to get the 2 garrison units into fighting.
1. Move corps 1x NW of Essen to 1x N of Arnhem and attack and attack garrison in 1xNW of Arnhem. Advance after combat.
2. Move the garrison 2xSE of Arnhem to 1xNE of Arnhem and attack garrison in Arnhem.
3. Move the garrison 1x NW + 1xN of Scholven to 1xN of Arnhem and attack Arnhem. Advance after combat. If you for some reason fail to take Arnhem you send a fighter to Arnhem to finish off the defender.

This is the situation after the first 3 attacks and the Dutch units are dealt with. Hague is left for now. It can be dealt with in turn 3-4.
4. Use fighter 1xNW of Frankfurt to bombard Belgian garrison 1x NE of Brussels. This attack serves 2 purposes. One is to engage the French fighter and the other is to deplete and drop efficiency on the garrison. This attack must happen first so the English fighter can't engage.
5. Use fighter 1xSE of Cologne against Belgian corps in Brussels. This will engage the British fighter and maybe inflict a step loss upon the Belgian corps.
6. Use the tactical bomber 1xS + 1xSE of Cologne to bombard Brussels. Expect 1-2 step losses on the Brussels corps.
7. Use the strategic bomber in Scholven to bombard the garrison 1x NE of Brussels.
8. Use tactical bomber 1xNE of Cologne to bombard the Antwerp garrison.

This is the situation after all the airstrikes.
9. Use corps 1xNW of Scholven to 1x NE of Antwerp to attack the Antwerp garrison . Do NOT advance after combat. If the Antwerp defender is still alive you use the Corps in Cologne and move it to 1x SE and attack. Then you advance into Antwerp. Then you use the armor unit 1x NE of Cologne to move 1x SE of Antwerp to attack the garrison 1x NE of Brussels
10. Use corps in Cologne to move to Antwerp and attack garrison 1xS of Antwerp. Do NOT advance after combat. If the unit is not destroyed then you use the armor unit 1x NE of Cologne to move 1xSE of Antwerp to attack the garrison 1x NE of Brussels

This is the situation when Brussels is stripped of its defenders.
11. Move the German mech unit 2xN of Cologne to 1xNE of Brussels and attack Brussels. Expected Brussels losses is 3 steps.
12. Move the German armor unit 1xN of Cologne to 1xNW of Brussels and attack Brussels. Expected Brussels losses is 2 steps.
13. Move the German armor unit 1xNE of Cologne to 1xN of Brussels and attack Brussels. Expected Brussels losses is 2 steps. Advance after combat to force a Belgian surrender.
With this option you have a chance to use 3 units against Brussels to increase the odds. If you get unlucky in the beginning then you designate the rear armor unit to finish off a Belgian unit protecting Brussels. Then you still have 2 units against Brussels as you had before.

This is the situation when Belgium surrenders.
The major upside to this way to deal with Blitzkrieg turn 2 is that you get a bigger chance to capture Belgium in 1 turn.
A side benefit is that on turn 3 you have 2 armor and 1 mech unit at the front line that can immediately go after French units.
The major downsides with this way to deal with Blitzkrieg turn 2 are twofolded:
1. The rail transfer cost is considerably higher since you need to get an extra armor unit to the west instead of a corps unit.
2. The invasion of Poland is weaker so you might not even take Warsaw on turn 3. Then you may need to wear down Poland in mud weather.