That's exactly what I'm saying. Just because they are made by the same brand doesn't mean that they are exactly the same.
Check out the construction of the France shirt vs the Lions one:
http://www.adidas.co.uk/men's-ffr-home-authentic-jersey/Z18649_700.html (Mesh under the arms, different seams, etc)
vs
http://www.worldrugbyshop.com/37508.html
The Lions shirt is closest in template to the All Blacks shirt - but even then, it's not identical. I can't find a good picture of an authentic though.
The "problem" with the Lions shirts is that the way they have done the stripes in the body material means that the shiny stripe has almost no stretch whatsoever. This is a problem at the narrowest part of the shirt just under the HSBC logo. Very difficult to get on and off for me. If the material didn't have the stripes, or there were mesh inserts, this wouldn't be nearly as much of a problem.
Neither the France, nor All Blacks shirts, have this issue, and I actually suspect that by not having the stripes, the plain material can actually have a bit more stretch. It doesn't need much - but none makes a big difference. I have seen a test All Blacks jersey in a store from just after the world cup, and it did have a very similar hourglass shape, but a decent amount of give.
As for the comparison with the Wales shirts - please see the attached pictures (apologies for the selfies).
The RWC shirt is a test shirt size small. It's snug, but I like it.
The regular Wales test shirt is a medium. A bit bigger than I like, but I bought it for a collection.
The Lions test shirt is a medium. It is CRAZY tight in the middle with no inserts/stretchy panels and very difficult to get off.
The small Lions test shirt I sent back had the same under arm measurements as the small Wales RWC shirt - 18". The medium Lions shirt I have has the same under arm to under arm measurements as the medium Wales shirt - 19" BUT is only 15.5" across the narrowest part. Get a piece of string. Make a 31" circumference circle. Try and get it over your shoulders. If you cannot, then you need a Large and it will be baggy at the bottom like all of the current players.
Hope this helps.
View attachment 2322View attachment 2323View attachment 2324