737 weird question
 

I was asked a werid question:why is the wing anti-ice bleed vents sequenced like this? 4-2-3-3-2-4?

The numbers refer to the slat positions to which hot air is applied.
The outer leading edge slats are not heated, nor are the leading edge flaps.

I dont think so.
The WAI bleed vents are in such sequence for proper heating.
Each slat has a WAI bleed duct located in the middle of it,each duct has 2 spray tubes that go left and right if you will and discharge bleed air.
So i think,on the left and right side of the duct,if you look facing the slat,you will see 4 vent holes,the mmax numbers as this where the bleed "spraying" temperature is at its hottest,then as it travel along the left and right side,there will be a 2 hole vent...only 2 as to avoid the air to vent too much and cool down too early before reachinqg the end of the slat where finally it is vented out via 3 holes.

So it goes like that ,slat 1:,324423,slat 2 :324423,slat 3:324423