Units that shamble (mostly undead) cannot MOVE at the double but may CHARGE up to twice their movement.
MY confusion is with a unit that can also Fly and has the shambling characteristic.
Can “wraiths” Fly at the double?
Can they Fly charging up to twice their movement?
Thanks for your words of wisdom.
Fly just sets their speed stat to 10. After that, they follow normal rules for movement (with some exceptions, listed in the Fly rules section).
So wraiths cannot move at the double, but yes they may charge which is always double speed.
Rules in KoW mean what they say, not more, not less.
You’re trying to conflate things that are separate rules even though they sound similar.
At the double and charge are different move orders.
The movement distance usually being the same doesn’t mean anything other than that. Rules that apply to one do not apply to the other because of a coincidental similarity.
Shambling means that a unit may not use the “at the double” movement order (unless scouting).
That’s it.
Shambling has no effect on any other movement orders.
Fly applies to moves by a shambling units in the same way as any other unit, there’s just one movement order that isn’t allowed.
Do note that the fly special rule does not apply to movement due to the surge spell though.
Thanks for the blazing fast response,
(tho I wasn’t trying to conflate, sonicate, or flatulate anything… simply trying to get some clarity)
As I understand your explanation a flying unit (let us use wraiths) can fly at the double, passing over an enemy unit with enough movement left to clear that enemy unit, turn 180 degrees (because they are nimble) and land one inch away from the rear of the enemy unit. Then in the ranged phase, a necro (within 12 inches) cast a surge spell with enough hits to allow the wraiths to strike the enemy in the rear, as a successful charge with 3x the number of hit dice - correct?
wraith no, since they have shambling.
another unit with fly however, can move at the double if they do not have shambling.
fly over and turn 180 degrees - if they move at the double, no pivots are allowed. if they have the nimble rule however, one pivot of 90 is allowed.
if the fly over with normal move (not at the double) they are allowed one pivot + one if they have Nimble. these two can indeed be combined into a 180 degree turn by flyers who are flying over things. if the flying unit took any damage in the previois melee phase however, they cannot Fly, so any pivots must be turned and end in a legal position (90+90) and can not be combined into a single 180.
Wraiths may not move at the double, because of shambling.
Also, nimble will only allow one 90° turn with an at the double move.
A nimble flying unit could fly over an enemy unit and turn 180°, if an advance (normal move) would clear the enemy and end outside of 1".
If a spellcaster with surge is in range and has LoS, then the unit could be surged into the rear of the enemy unit.
Got it! Thanks DarkBlack and Fred
No, fly does not set speed up to 10. That was the rule in 2nd edition. Fly only allows units to pass over terrain and enemy units unhinderd.
You are correct. In 90% of cases though, the unit in question has a written speed of 10. 
I am aware there are some speed 7 exceptions (and even a speed 6 exception?).
That of course is right. Mostly the Units that had Fly in 2nd Edition and kept their printet speed of 10. Woodland Critters have speed 6. I was really bumped when i wnet to a 3rd edition tournament with them and thought hey cool. Cheap chaff flyers with speed 10 
In the first match i learned that Fly was changed. -.-
They were still useful units.