Whatever about previous years, that's a misread of which current issues are more pressing than others.
Our current, first principle problems are in possession. We struggle to keep it under pressure, we lose it in the wrong areas, we struggle to play from the back and we struggle to progress the ball up the pitch. From that you get bad turnovers and struggles to deal with transitions, which is the secondary problem. But with us placing even more emphasis on possession with our choice of manager, those first principle problems have increased even more in importance.
The Brentford game highlighted the point perfectly. Our issues weren't in dealing with transitions, it was (as Toney said) our inability to deal with being pressed. "We knew the high press would effect them, and it did".
FDJ would have done more to address that primary problem, by offering a press-resistant and progressive option in that deeper midfield position. Casemiro doesn't. He addresses a secondary problem, which is how we cope in some situations once possession has already been lost.
Which is great. But if another team tries to do what Brentford does and press us in those areas, it doesn't help us much. There's a reason ETH's primary target was FDJ and a secondary target a ball playing CB. He knew getting more ability in possession in those areas was a priority.