I think you're totally misreading my posts then if you're reading what I've put as suggesting we play KdB in an unbalanced team. In fact I quite literally stated I'd drop him or Silva to field Navas so that we would have a balanced team. And in fact I am one of those posters who has been saying we played our best 5 matches without KdB & with Navas on the wing. Little confused why you're now repeating that back to me.
However on your valid point; I'd argue for the same reasons I'd have it the opposite way around. Against the better teams & away from home I'd like us to be far more effective on the counter, in which case KdB centrally wins out over Silva for me, he's far quicker to move the ball on, and with the pace of Sterling/Navas combined with his I'd fancy us to be more dangerous than if we try to go toe-to-toe and "dictate" the game; for example the game away at Arsenal, how did that go for us? Now don't misread this as me saying Silva is bad in these games, I'm saying it's far from a poor plan to have someone like KdB in a team for those sorts of matches.
Whereas against lesser opposition we need someone like Silva who can pick the lock against a packed defence & help us sustain pressure on an opposition, as KdB like you said often gives the ball away with his style.
You say KdB hasn't been effective in the big games, or away from home (you could also say the same for Silva, no?) however he's shoved out on the wing for almost all them matches, like I keep saying he's not a winger and neither is Silva - shoving them both out wide for matches, for me, is unbalancing our team & simply doesn't work. One or the other in the middle with 2 wingers (Sterling/Navas) out wide. Round pegs in round holes.
I think it's fairly disingenuous to suggest KdB is only good enough to pad stats against the bottom 6 teams at home only when Silva is tired. Silva has 7 assists 0 goals; all came against Sunderland (H), Newcastle (H), Watford (H), Chelsea (H) & WBA (A). He played against Arsenal (A), Everton (A) x2, Leicester (A), Stoke (A), also the CL matches; without exactly setting the world alight eh.
You could even argue KdB has performed better against the tougher opposition than Silva with goals against Spurs, Sevilla & assists in others, but really what I'm trying to show is that the whole team has underperformed in the big matches, thus picking out someone who probably statistically has performed the best whilst being in the wrong position for almost the entirety of the time doesn't ring true to me.
Summary if you don't want to read that:
Silva is absolutely my favourite player to have watched in a City shirt & still is, however KdB is also fantastic & both are easily good enough to play centrally & I think you're significantly underselling one of our best performers of the season (whilst playing out of position for probably >90% of the time).