true, not many IGL's have had the oppoturnity to do the same, but i still doubt you can name one IGL who has done the same thing.
fallen? yes, he is a legend in the brazilian scene and helped to elevate the country to relevance but he was hugely helped by cold, who was the 1st player to make his debut on the top20 list at top1. sk was a great team, but it was not fallen who brought them to life, it was cold, and his impact, freeing the rest of the team.
gla1ve? he was brought in after karrigan, who had established the foundation for the team and made the system relevant. sure, gla1ve has done a phenomenal job, but when he joined, he had virtually no experience in a tier 1 team. he has developed into a great IGL and player, no doubt
daps? great at finding new talent. brehze, ethan, tarik, naf, stewie, mixwell and now tenz. he is great at developing teams and creating a system, but doesnt do well at fragging. his curse is also to get kicked everytime he has established a system.
karrigan in the other hand has yes, had more chances and probably better players, but never came into an environment with an established ground. he built TSM back in the day with the astralis core. he made them a consistent top tier team, in spite of choking in the playoffs. faze? what he got when he joined was a team of castaways and he made them a working unit of championship contention. after krakow he had the privilege of working with a superteam, with whom he achieved a lot, but you could still call it underwhelming in a way. karrigan was kicked, and rain admitted alter that it was a huge mistake. after that, faze dropped into irrelevance. sure, they had bad form before kicking him, but it just made matters worse. after that, finding himself as a castaway again, he has built mouz into a playoff contender team in the matter of months. he has established a working system with roles, and keeps developing young talent like ropz and woxic.
yes, you can argue that he could have done better with the caliber of players he's had on his disposal, but i doubt anyone has come close in the era of cs:go. he is so far the best teambuilder there is and if you can show me solid arguments that prove me wrong, sure. until then i will keep my opinion as it is and respect him hugely for what he's done.
EDIT: the article where rain says he regrets kicking karrigan.
EDIT 2: also, i am surprised that hltv still has users who really can have a great debate without getting aggressive, respect to you for that.