OK ...

Let's for discussion sake ... say that from some perspective that a 6000' runway "might" look similar to a 12,000' runway (I'm not exactly sure I'm buying this argument?) ...

at some point, maybe in the flare(?), would you think something was wrong when your 211' wingspan (with both outboard engines over the grass) doesn't look quite right on that 100' wide runway?

I don't have easy access to a 747 Operating Manual ... how wide are the outboard landing gear?