you should know that the hardest thing about being an igl is to avoid being read. Faze played 4 maps with niko calling, which isn't too much, so they're hard to read atm (and it was even harder before the series against g2) Also, niko was the igl for mouz for quite a long time, and they found little to no success. He couldn't unlock his teammates' full potential, everyone played to help niko. When he went missing, mouz had no chance to compete against t1. If you need anymore arguments, read niko's interview, he talked about how faze needed something fresh, a wakeup call. And if you think faze could be top1-3 with 5 starplayers and basic calls from niko, consider the results of faze in 2016, before karrigan joined.