The best way (or at least the least dependent on luck) to beat CoP, is with a static of friends. Putting your success in the hands of random strangers is a crapshoot because players at any level can be radically differing in skill level. CoP is very unforgiving. Last time I read any statistics on it, only 25% of the population had completed CoP, and a good chunk of the remainder hadn't even completed prommies. Good luck on your prommie runs - I'm not too far ahead of you in CoP - I just unlocked access to Phomiuna Aqueducts and well anything else I say would be a spoiler.