lol a few weeks ago on iron banner I got an inv for iron banner to make a full team of 6 and they were all checking my grimoire which I think is like 4525 off the top of my head. I had the highest grimoire in that fireteam and while I don't consider myself to be the greatest player, I feel like I'm good and these people that were going on about KD and grimoire and blah blah who were all higher light than me were getting there asses kicked and I led my team almost every time. So I guess it just depends. grimoire can be a hit or miss on determining someone's skill.