I agree with you, it's hard and it take time.
Look the danish exemple : they had 2 igl : karrigan and MSL. When they kicked karrigan, they picked gla1ve, it took time for him to be on par. But yet watch what he accomplished since.
In french scene, when an igl leave (ex6/happy) another player of old roster take the lead.
That's a short term solution and short term is not good to reach the top usually.