Speedbrake deployment angles for 320:
AP Off: 3+4=40 degrees, 2=20 degrees.
AP On 3+4=25 degrees, 2=12.5 degrees
321: AP On or Off:
2+3+4 = 25 degrees.
That's why the spoilers don't work so well on the 321. My bet is the 319 is the same as the 321, but could well be wrong!!