Yeah our best players didn't have a good day on the field. However, I think North Melbourne simply have the upper hand against us. We won the contested possessions against them in the Round 6 game, but still lost.
I have mentioned this before, but outside of Round 23 last year (where North played their VFL side), North Melbourne have not scored any less than 100 points against us in a match since 2009. That covers the entire reigns of Damien Hardwick and Brad Scott at Richmond and North Melbourne respectively. In contrast, we have conceded less than a 100 against every side at some point in 2015, let alone the last 6 years. They just match up really well against our defence.
Therefore, the problem may not have been the EF in of itself this time around unlike the past. It may have just been our strategy going into games against North Melbourne altogether. What the problem is though, I can't tell you.