Linked just for reference, I appreciate your link as well.
I read it.
I haven't read the several statutes it cites.
The actions being taken in the EO are fairly clearly stated, and none of them amount to "build the wall."
Connect the dots to the EO of some weeks ago turning over presidential perogatives s to SoS and SecDoD ... And give credit to Trump for figuring out ways (plural) to get the job done. And that does not preclude the continuing opportunity to do a DACA deal on ever increasingly better terms I.e. the art of the deal ;)