mismatch between loadout pylon and selected launcher

I have observed a strange mismatch between the pylon loadout in the mission editor and the chosen pylon in flight:

1. Weapon Selector is set to AA Missiles, Launcher 1.

2. By pressing fire a missile launched from left INNER pylon.

3. Pressing fire again a second missile launched from left INNER pylon.

4. Left INNER pylon is empty now.

I would assume that launcher 1 is pylon 1 from the loadout menu. But pylon 1 in the loadout menu is the left OUTER pylon?

Pylons in the loadout menu (frontal view):

(right) (center) (left)

5 4 6 3 6 2 1

Is this a bug or some strange concept I just do not understand right?

EDIT: The loadout in the mission editor seems not to be corellated with the actual launcher in flight. Rightmost is numbered 5 and thee is no launcher 5 on this bird. So 1-2 must be the inner launcher and 3-4 the outer ones? Correct?

EDIT2: The launchers are numbered as follows (left to right): 3 1 2 4

yep you got it

Yep, it is mentioned in one of the training missions :

Inner pylons are from left to right : 1-2

Outer ones : 3-4

Perhaps the DCS mission editor has no way to display crazy Russian pylon numbering schemes. If you think the one on the MiG-21 is bad, consider how it works in the Su-22:

1 - front left fuselage pylon

2 - front right fuselage pylon

3 - left outer wing pylon

4 - right outer wing pylon

5 - left inner wing pylon

6 - right inner wing pylon

7 - rear left fuselage pylon

8 - rear right fuselage pylon

9 - left middle wing pylon

10 - right middle wing pylon

Using both the 1 and 7 stations or the 2 and 8 stations by a single weapon system is called 1s and 2s respectively. Also, there are two smaller pylons next to 1 and 2 called 1r and 2r.