I am 5'10 186 I wear a L in Kings jackets and a 38 in their pants.
The massif jacket i can put on and zip up but its tight id say it fits like an athletic cut medium. ( I wear a L massif at work idk why the army versions are in these weird sizes.)
The pants I can get on and button but they are tight in the legs and thighs id say they fit like a very slim cut 36/34 maybe 32 in kings.