So every setup sweeper is now using a choice item over a life orb (screw mixed attackers). This is a (1.5/1.3)x boost, or 1.15384615.
Every defensive mon has 1.5x to both defenses.
1.15384615/1.5=.76923077 with just items being taken into account. So far defensive mons have the advantage
So when something uses Earthquake it gets double the power now, as it would almost certainly have been using Earthquake before (Pdon is banned, I can't think of any physical attackers that get Earthquake that use any other Ground move besides Marowak, and conveniently Bonemarang has the same bp as standard EQ.)
2x.76923077=1.53846154
A non-mega set-up sweeper is now doing about 1.5x more damage than it would have done before. Abilities change this, for instance Tough Claws or Sheer Force would push this farther. Multiscale wouldn't help because everything that gets it is Flying type anyway, but Heatproof and Thick Fat do help. Stallrein op.
What about with Dragon Rush? You aren't doubling damage here, because you were possibly using outrage before for your huge damage output.
200/120x.76923077= 1.28205129
About 1.3x more damage. Also flinch chance. Keep in mind that by using eviolite you lose passive healing, and the new choice items have no drawbacks.
Now Thunder/Blizzard over Ice Beam/Thunderbolt
110/90x.76923077=.94017094
A very slight drop in power... But not enough for me to care that much honestly.
I'm not really good at the maths so if I screwed up please tell me.
Also problems with this: I assumed base Life Orb. I ignored abilities and their effect on the metagame. Actually screw the lack of abilities I'll do a little of that below.
So back to the .76923077. (So to keep things clear, partially for myself at least, this is going to be calcing the effects of a choiced mon with given offensive ability v an eviolite mon with given defensive ability)
With Thick Fat or equivalent (x1/2): .38461538
With Filter or equivalent (x3/4): .57692308
With Tough Claws (x1.33): 1.02307692 (Note: Remember this calculation includes a choice item, so ZardX or Mega Metagross is still doing less than this. Actually this is only relevant to Barbaracle a
nd Binacle. Why did I bother.)
With Sheer Force (x1.3): 1 (Isn't this nice. And much more relevant a calculation.)
With Sheer Force v Thick Fat: .5
With Sheer Force v Filter: .75 (lol i was lazy and didnt calc these last two)
With Technician or equivalent (x1.5): 1.15385616
With Technician v Thick Fat: .57692308
With Technician v Filter: .86538462
Using Sheer Force choiced Dragon Rush is just like using a standard Dragon Rush with better accuracy (and no flinch chance because Sheer Force). Good thing that's going to be so common.
Notably Miltank is the only non-mega with Thick Fat and non-rest recovery, Bronzong, the only mon with Heatproof has no recovery, and nothing with Filter or Solid Rock has recovery. If you want me to calc another defensive ability I forgot tell me.
And of course Dragonite is amazing.
What you should take away from all these numbers, imo is that there's not much of an inherent advantage for defensive mons before you consider the increase in base power of attacks (except for things with Thick Fat or Multiscale), and afterwards there's a clear offensive advantage. This is presuming no drastic changes like choice items being reworked.