The FL jacket is tagged 44, The Canvas Thedi is tagged XXL, The Markos ealier above was just XL, LW tagged 46, Johnson M500 is stock size 40, Langlitz didn't put a tag in my Cascade, I will ask on my next one, La Brea is tagged 44.
The FL jacket I have now is from his sale page that was meant for someone taller than me with 27" sleeves straight down. All other jackets are 26" sleeve length (+/- 0.5") range except Langlitz I asked for extra length but it goes air tight so hard to tell.
Every jacket above is rocking about the same chest width, 23" plus or minus half inch, with the exception of the Cascade which is 24" or 26" with the footballs. That was ordered as second loosest fit with sweatshirt under. So if you want slimmer Langlitz, they have the super tight fit option too. It reminds me mostly of my Lewis Mk1. Almost exact same jacket but made from two very different shops. Did Ross Langlitz have British family roots?
What I was trying to get across was that, and you may find this subjective instead objective:
1) square shoulder isn't "bad" everyone has one or more.
2) there are similarities across brands, never exact the same, but similar yes.
The trick is to find out what their tag size means. Everyone measure or look at their measurements different than the next person. But one of the size from every brand will fit just about every one. I had trouble with Greg's size 42, and I bitched about it. I felt it was unfair for him now looking back, so I am trying to write a similarity comparison review. I go through this pain joy bipolar emotion with every single brand. Try to find out what their sizing is. But I am very certain that a size in every brand will fit me. Sometimes two. I just don't know which one until I get them...
My sale page Greg jacket was machined better than my (second hand) custom ran La Brea, but no more than my Rainbow Country batch ran jackets. They are same level in terms of machine skills and quality. Rainbow Country makes the very best machined products in my experience, and now Greg too. But they don't make every thing and they don't make every size. This is why I am still in Greg's queue. I want a Rainbow Country made Peters but it's not available from Japan, not in navy with caramel contrast stitch.
IMO the trick is to ignore tag size as it means nothing.
Also, this statement: "But one of the size from every brand will fit just about every one" is absolutely untrue.