Irene is on August's level. Her dragon form gives her a massive advantage in terms of physical stats, and the wisdom of a sage dragon gives her access to her best attack. However, this comes at the cost of her becoming more vulnerable to dragon slaying magic. I see no reason why August can't copy dragon slaying magic, and indeed the melt spell he used against Natsu was probably just that. Overall, both August and Irene have the means to take each other out.
Also, Erza and Wendy gave Irene an extreme difficulty fight. They didn't beat her, but Erza broke Irene's strongest enchantment and then cut down her dragon form. Unless you believe Erza is just leagues above Laxus and Jellal combined, then there's simply no way this fight is a stomp. It's at least a high difficulty fight.
Ah, I got what you mean.
Well, Dragon Eaters aimed to slay Dragon Gods. It's pretty clear that if they have that aim they really believe they could do it.
And what part is hilarious with statement about their "Acno-levels".
It's just sarcasm on some posts - if you say DG are on Acno level, you should say DE on same level too. And someone who expect DE are on same level with Acno.. well.
So, all I said, they're not on Acno levels, re-read it better. But some guys had posts like "DE ate Acno arm", "DE could slay Acno if knew about him .. etc"
Dragon Gods are on Acnologia's level simply because they were introduced as such. Unless you believe that Hiro Mashima is just trying to mislead us, then there's just no reason not to take it at face value. At the very least, the god dragons should be on the same level as Acnologia in the way Igneel was. One of them is even Igneel's biological son.
The Dragon Eaters don't think they could take on a god dragon head on. They only made their move on Mercphobia after finding out he was weakened, and they wanted to weaken Aldoron before making their move on him too. More importantly, the run away when fighting people far weaker than the god dragons.
