Looking at David's resurgence then Isco could find himself in the same predicament as Madrid, I think that may be a stumbling block as he'll want some kind of guarantees... he's potentially outstanding but will he improve to that level without the consistent game time he craves...
Bernardo is bang on the type we should be looking at, attainable and would fit in seamlessly, he's also another level in terms of creativity..
Silva's resurgence has come from an increased aggression, working hard in defence, getting stuck in and really becoming a proper all-round CM.
Isco can definitely do that, could Bernado Silva? I don't quite see it, his lack of defensive effort/ability was one of the things that got us back into the game against Monaco.
I would suggest that Bernado Silva would be the perfect replacement for the David Silva of 2010-2015, but that Post-Pep Silva is much more comparable to Isco. The price difference would be stunningly big as well. Talking about £25-30m for Isco in the last year of his contract and £80m+ for Bernado Silva with just the 2 years age difference.
As for game time, I think the idea that Isco could hold the pivot role interesting against smaller teams, but even if he's only seen as a replacement for the KDB/Silva spots, we have a massive advantage in that Pep rotates, Zidane does not.