I like the steel slat fence as long as that steel is hardened to the point it would be very hard to pry apart.the slats would have to be close enough so that children or anyone else for that matter could slip through.
Make it 30 plus feet tall and put razor wire on top.if its built like that I’d be very happy.
A steel slat fence would be many times better than the border barrier we presently have.
There is a lot of potential in this design for specific add-ons in problem areas.
If they are going over the top with a rope system a sharpened 3/4" thick by 4" tall cutting bar can be welded to the top.
If they switch to a metalic solution an elecrified insulated busbar on the US side (cant be seen) would provide shockingly good results.
When the solid framework is already in place, custom solutions are a snap.
And yes, razor wire is an additional soultion already in use! .