I'm sure a lot of you guys have all ready seen this, was leo that clued me in but here.

http://www.ffxiah.com/forum/topic/30058/dev-legion-follow-up/

So the way im thinking it is this. They say 36 man has roughly 50% more hp then 18man. So the way im figuring

18man = 100%hp
36man = 150%hp

They said they want to make 18man half the HP of the 36man.

150% x 0.5

75%hp

So in essence it seems like a a -25% hp nerf for the mobs in 18man. Should be pretty helpful for us taking on tier 2.