Hi
Considering a hypothetical hand here from Example 4.12 at
http://en.donkr.com/Articles/plo-from-scratch---part-4-589

I am summarizing it here
$10PLO 6-handed
Villan in CO ($10) raises to $0.35, Hero ($10) has Ts 8d 7c 6s on the button. Hero 3bets to $1.20, Villan 4bets to $3.75
CO is a loose raiser who respects 3-bets, and he tends to play tight out of position after getting 3-bet.
Hero now assumes CO has AAxx AND will shove any flop and we can cherry pick to stack off the ones we like

From Villan's perspective :
Villans manages to get in 37.5% of his stack preflop with AAxx and plans to get it in on any flop.

From Hero's perspective:
We have 41.54% equity preflop,
The pot is $7.65 on the flop with $6.25 stacks remaining, When CO pushes the rest of his stack in on the flop, we're getting pot-odds (7.65 + 6.25) : 6.25 =2.22 : 1. So we need 1/(2.22 + 1) =0.31 =31% equity to have a profitable call which will obviously depend on the flop.
From the equity distribution curve of our hand vs AAxx (propokertools), we have minimum 31% equity on more than 60% of all flops. So we will find enough equity to call more often than we fold. For this reason, we decide to call the 4bet.

This article implies that due the above reason, we can profitably call the 4bet to crack AAxx but looking at this from Villan's perspective, I see this advice often given about playing AAxx
If you can get at least 1/3 of your starting stack into the pot preflop in a heads-up scenario (so that you have at most 1 pot-sized bet left in the stack on the flop), you can push all-in on any flop if you want to, and there is nothing your opponent can do to exploit it.

The way I see it, only one of the statement can be true

Villan playing un-explotiable by getting more than 1/3 of his stack in preflop
Hero is exploiting villan by profitably calling the 4bet with these stack sizes and can stack off on the flops he likes

So I am not sure who is exploiting who or if we have some sort of equilibrium in this very specific spot.

Thanks in advance !