I didn't notice that in the yalen battle yesterday on EU3. But in the Kutt vs Templars themed battle from Tuesday night it was horrible (on NA3). For the first 15 minutes I didn't notice any issues, and then later on in the battle I would click to attack and nothing would happen. Half the time I clicked to attack my guy wouldn't swing. And this was on NA1, I'm from Minneapolis and had 30-40 ping the whole time. In the battle server with 100-120 people I consistently have 200-250 FPS. In strat battles I was getting 50-150 FPS (generally around 70fps), so it wasn't like my fps was completely down to nothing when this was happening.
As far as I could tell, the server was just not registering that I was trying to attack. Maybe the NA server is just shit compared to the EU server's hardware/resources?