It is interesting what some people chose to focus on for various reasons. So what is the importance of scale for these purposes anyway. As Damian and George have aptly noted, for miniatures scale between manufactures is actually irrelevant if there are other reasons (again as noted) why you would not display the figures and vehicles from these manufactures together. For me, a simple look at the photographs of the FL and K&C WWII figures makes that point extremely well. So as much as part of me would like to see a common scale standard uniformly applied for all of these products, it isn't going to happen and for the most part, it probably doesn't matter so long as the manufacture is consistent its scale within a given line.
That said, there have been a number of loose observations here about scale that appear in need of some refinement. So in the interest of improving the science of the scale issue, rocket or otherwise, let us examine some facts about figure scale.
When considering vehicles or other tangible items of known dimensions, it is relatively simple to discern the scale of an item by comparing the size of the original with the size of the model. That is obviously (maybe less so to some) not as simple for persons since (unless you are intending to model a person of known height you have to first assume an actual person height. For an adult male, that can vary quite a bit as I have noted several times before but most for this purpose seem to just pick an average height. Once you do that, as Matt noted, you simply divide the size of your assumed person by the measured size of your figure and the result is your scale. I went through this exercise in some detail for K&C, FL, C&S and WB Napoleonics with measurements in the this thread
http://www.treefrogtreasures.com/forum/showthread.php?t=13464
Anyone interested can refer to it or not as your cognitive dissonance permits.
I have no WWII figures of any kind to measure so I can't do quite the same thing here but I can note that the observations made by some about K&C being 1/30 scale and FL being 1/32 scale just do not hold water. How can I say that? Well perhaps the following table will help explain.
Essentially this is a copy of a simple spreadsheet to show the scale resulting from differing actual heights (across the top or X axis) and figure heights (down the side or Y axis). I chose to convert inches to mm since figure measurements in mm are more precise. The conversion factor for inches to mm is 25.4 as noted. So using this you can take your own measurements and draw your own scale conclusions depending on what you want to assume for height. The use of weapons (as noted sometime ago by Ken and referenced in that prior thread) is obviously a better scale indicator but the discussion here has focused on height so lets stick to height for this purpose. To give an example from the table if you assume a six foot person (72 inches in the table) you can easily see the implied scale for a 60 mm figure is 30.5 or 1/30.5; similarly for 5 ft, 10 inches person and a 58 mm figure it is 30.7.
So how does that apply to what information we all have here. Well looking at the one measurement photo we have comparing the two lines on the FL website
http://www.firstlegionltd.com/images/Figure Scale 1.jpg
I think the following observations can be made. Some general observations are needed before considering the values. Since these measurements are taken including the base, you must know the base thickness to be precise. My FL Napoleonic bases are 2 mm and my K&C ones 3 mm. The bases here appear no larger and if anything slightly smaller than the FL Napoleonic base so I would say 1 to 2 mm. As to the figures, the K&C figure is nearly upright and the tallest FL has slightly bent knees. This suggests that the FL upright figure size is a bit, likely 2 mm or so, taller than shown by the tape. Looking at the photo and attempting to disregard the hat, the K&C figure appears to measure 64 to 65 mm and the FL one 58 to 59 mm. Adjusting for the bent knees the FL one seems more like 60 to 61 mm. With the bases subtracted, this would be 62 to 64 mm for K&C and 58 to 60 mm for FL.
So what does this suggest? Frankly I think an average figure is closer to 5ft 10 than 6 feet but let's consider both. Returning to the table this would imply the following scales for the following heights:
K&C: 70 inch person 1/28.7 to 1/27.8; 72 inch person 1/29.5 to 1/28.6
FL: 70 inch person 1/30.7 to 1/29.6; 72 inch person 1/31.5 to 1/30.5
So if this truly matters to you take your own measurements and do your own table but I have to say to me it seem pretty clear that the K&C figures are closer to 1/28 and the
First Legion ones closer to 1/30. Of course depending on your science degree and the nature of your homework, your actual results may vary.