Mobs doing too much damage?

I've been playing this game for 6 years, I like to think I know how much damage a mob does. I downloaded the better together beta all happy and whatnot. I make progress like normal and get full iron armor. I fight an enderman and his damage was mental. Despite fill iron, he was doing 4 hearts a hit, 6 of he had a block in his hand. I found it strange, but adapted. Than I go into the nether. And I stopped. Doesn't help that the ghasts are flying at light speed and are LITERALLY impossible to hit do to this ludicrous speed and their fireballs doing about 3 damage AND launching you up into the air. Never remember them doing that the past 2000 times I've fought a ghast. The fire effect duration is punishing to, doing about 5 hearts over the course of the burning. Blazes were fine for the most part. And than I found a wither skeleton. I've never seen anything so unbalanced. Not only does the stone sword do 6 DAMAGE, the wither effect kills you regardless. And this is with full iron armor, mind you. I than whipped up another quick set of iron armor and weapons to run back in, and I saw a magma cube. I know These things are a joke, a run up to him, slap him a couple times, he slaps me for 4 hearts, I get back a bit startled by his damage, he duplicates into 4 pieces, one somehow behind me despite my 3 block range, the small ones do 3 hearts per attack, I'm running for my life.
Is it a weird glitch that makes it so my armor doesn't count or did you guys just horrifically mess up on the game transfer when porting it to this version.