Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
No. As mentioned in the requirements on the site you linked to, only iMacs can be used as displays in Target Display Mode.
 
Have the use of these two laptops:
MacBook-Pro Retina (2012).
MacBook-Pro Retina (2014).

Is it possible to use one in Target Display Mode (& drive) from the other?
Presumably via a ThunderBolt Cable.

No guidance here:
https://support.apple.com/en-us/HT204592

No. Only iMacs support Target Display Mode. 27" 2009/2010 iMacs over Mini DisplayPort, 21.5" or 27" iMacs mid 2011 - present (excluding the 5K) over Thunderbolt. That is it.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.