At the beginning at ROCH, Guo Jing had quite a fight with West Venom AYH, and as a result, they are both injured, however there are two points to make :
1 - GJ was holding back because he was trying not to hurt other innocent people when fighting AYH.
2 - GJ was able to recover faster than AYH due to his 9 Yin Inner Power training since LOCH.
So we can conclude that at the beginning of ROCH. GJ is better than AYH with his reverse 9 Yin training.
Since AYH = H7Q during their last fight to the death, which happens several years later, and assuming 9 Yin and QZ training will only make GJ's inner power greater and better over the years, we can also assume that GJ is better than those two Greats.
When GJ fights with GWM, it is stated that GWM had better inner power cultivation but GJ has a better techniques (with 9 Yin off course).
Now that leaves us the question... How great is Guo Jing at the beginning of ROCH, compared to South Emperor Yi Deng, East Heretic HYS, and his sworn brother CBT ?
And what about with GWM, GJ has a better technique, so does it mean that he is about equal to GWM or better ?