Marcos Llorente isn't rated by Julen and Kovacic is gone, that's 2 midfielders less. Fede Valverde can't be your miracle man behind Kroos-Modric-Casemiro, I really rate him but it's too much for him. I don't see Ceballos and Isco playing a consistent midfielder role, but if Lopetegui gets any of them fulfilling that deeper role instead of an attack front 3 or trequartista role, then sure. But that's a bet, it's not a safe decision with safe consequences. I see more potential for that MF role in Ceballos than in Isco tho. And none of them can play the Casemiro role, Real Madrid has nobody to be his sub or to rotate as Marcos Llorente doesn't fill Lopetegui's eye.
I have nothing against Real Madrid developing their youngsters, they have some massive potential talents there. But remember: even Barça, when Valdés, Puyol, Xavi and Iniesta appeared with Van Gaal, won almost nothing. You can't put all the weight of a team in the youngsters if you want to win big trophies. If you don't want to win trophies but simply developing youth no matter the consequences, sure. But no coach lasts more than 1 year in Madrid without trophies, you know it well.
I'm not saying he's the panacea, but can't compare the Toby from Atleti to the Toby from Spurs. I'm not saying he's gonna make the difference, but you need something more, and there's little more available. I rate De Ligt, but that's another youngster. You also need already made players with 26-29 y.o.
But anyway, it's simply imo.
PS: I don't see how the hell Eriksen could solve anything of this btw. It would be a completely redundant signing imo.