As his Id points out, he already knows what Harry knows and vice-versa. That makes sense, because they are the same mind. The same soul.
I don't underestimate the Za Lord's guard, but I wouldn't underestimate Eldest Gruff either, who was a far more seasoned fighter than Aurora. Aurora may have been strong, sure. But as Harry shows time and time again, power is hardly the most telling factor. It's about talent, skill, will and experience. It's about planning and adaptability.
And the Za Lord's guard were not as formidable and organised in Small Favor in Battle Ground. The horde that is summoned in Battle Ground would be hard for anyone to deal with, I suspect. But then again, it all depends on who he was fighting (and when and why).
I suspect we will get some clarity about Harry's emotions and trauma...but who knows how much? I wouldn't mind the three stooges routine, it would fit Harry (although it's only really him and the Id, who is also basically his subconscious).