layout-large should be also include layout-sw600dp

The smallest-width qualifier is available only on Android 3.2 and above. Therefore, you should also still use the abstract size bins (small, normal, large and xlarge) to be compatible with earlier versions. For example, if you want to design your UI so that it shows a single-pane UI on phones but a multi-pane UI on 7" tablets, TVs and other large devices, you'd have to supply these files:

res/layout/main.xml: single-pane layout
res/layout-large: multi-pane layout
res/layout-sw600dp: multi-pane layout
The last two files are identical, because one of them will be matched by Android 3.2 devices, and the other one is for the benefit of tablets and TVs with earlier versions of Android.

It might be better to explain this on your page for flexible layouts.