Android : Alternative to using dp-width as discriminator for different layouts?

I'm creating an android application which is supposed to run on multiple different devices with notably different physical screen-sizes. The recommended way to do this seems to be the discrimination of screen-sizes via the device's dp-width, eg creating a "layout-w700dp"-folder for the corresponding devices.

I tested my application on a Samsung galaxy Note 2 (5.5") and a Samsung Galaxy S4 mini (4.3"). They both display the layout differently due to the available space and thus need different layout files.

Here's the Problem: They both report a dp-width of 640. The Note has a dp-factor of 2 with a pixel-width of 1280, the S4 mini has a dp-factor of 1.5 with a width of 960px. How can I use different layout files for the devices? There's indubitably quite a huge difference in physical size and I quite honestly wonder for which reason the "Device Independent" measurement reports the same width for each device.

Is there any other way to use different layout-files per device?

Thanks in advance!