According to "Ecology of the Troglodyte" in Dragon #235, it's not that they stink per se, but that they use scent to communicate.
...the overpowering stench that can reduce a human opponent to weak-kneed vomiting during combat with troglodyte, is merely the build up of olfactory battle cries, combat orders, screams of rage, pain, and hunger, and other smell/phrases which are spoken/emitted in such profusion that the combined smell overpowers non-troglodyte.
The scents they describe are many and varied; in fact the name of the trog in the piece is "Rose-Boiled Cabbage-Mild Skunk" as his name is a mix of those scents. But to the average human, more than one or two scents at a time just smell like "stank."
Retreat is for when you all need to run!
Fighting withdrawal is always better for disengaging from combat, if it will actually do the job. A withdrawal only works if the opponent is unable or unwilling to follow to maintain the combat engagement – if they do, you've wasted a turn failing to disengage.
The other purpose of a withdrawal is to back into a more favourable position – into a doorway or narrow hallway, for example. However, if that choke point is beyond ½ your movement, then you have a dilemma – a fighting withdrawal won't get you there in one turn. If time is of the essence, do you try to do it in two turns of withdrawal, or do you break engagement to flee to the superior position and risk a strike at your back?
The difference between them is always that, sometimes, those few feet of difference can be worth the risk. If they're not, then a Retreat action isn't worth considering.
And yes, the monster gets its attack. Turn order is merely a game convenience for play simplicity, and for representing a slight combat advantage, but really every attack (by creatures that survive the whole turn) are considered part of a simultaneous mêlèe. The retreat grants that extra attack – as GM you can roll it at the time of retreat, or on its initiative turn, and the difference is a matter if convenience rather than whether the target is still viable. Think of it as happening "sometime" during the turn when the retreating character exposed themself to danger by recklessly turning tail, but do the actual roll and damage whenever is most convenient.
Best Answer
In AD&D 1st edition inches of movement represents three things.
6" = 60 feet per turn exploring a dungeon. This allows for the normal checks for surprise, mapping, detection of secret door, etc.
6" = 60 yards per round moving through passageways. Basically if the person or party is in a interior location that they know they move at this rate.
6" = 60 yards per round moving outdoors like in a city.
6" = 6 miles per half-day treking.
This is all found on page 102 of the AD&D players handbook.
And to be complete for range (both spells and missile weapons) there is the following.
1" of range = 10 feet indoors 1" of range = 10 yards outdoors
This represents the ability to lob missiles in an arc outside as opposed to a flat trajectory indoors.