As I have come to understand it blowpipes now have an 18" range, right? or are they still 12" range but skinks get an extra 6" of movement for a total of 18". Hows this work here?
It is not 18 inch range (That would be nice). Skirmishers can now march and shoot. That gives them an effective 24 inch range (for one shot or javelins) and an 18 inch range for double tapping (as long as you are within close distance).
Yeah it is an 'effective' range not a proper range since skirmishers can now march and shoot, you can march then launch blowpipes their full distance.
As others have said it is an "Effective" range that you will get to use poison. You can March and shoot, and double tap. Skirmishers start at 4's to hit with WS3 effective range 18" = 12 inch march, double tap. So that 4 to hit becomes a 6 to hit if your at short range which is 6". effective range 24" = 12 inch march, long range. so again you need 6's to hit but to take advantage of poison in this instance you cannot double tap. If you double tap it is 7's to hit and you lose poison.
Therein lies the beauty of that unit of chameleons! The Chameleon unit starts out hitting on 3s, so you can march them 12 and shoot 12 and still hit at long range for poison. Love those chameleons!