It's not about people being carbon copies, it's more about putting together individuals that have some level of respect toward each other or at the very least, a connection (whether it be sports, family, etc...) to build on. There was no debate that Robin and George and Gayle and Charlie had 'something.'
Just being colleagues and 'hoping for the best' isn't enough to make things work.
For example, if Don is the centerpiece, then you surround him with people he can relate with and respect. It's great Poppy and Kaitlan are friends, but this wasn't a 2-person show. Simply put, the three of them together just didn't make sense from the start and by their own accord, they said.. "the show immediately struggled, with the original trio of anchors — Harlow, Kaitlan Collins and Don Lemon — noticeably lacking on-air chemistry and reports of infighting."
Had more thought (from top to bottom) been put into CNN This Morning, maybe things would have turned out differently....