Good articles, thank you, one of them pointed me in the right direction. This one helped me along them as well: https://www.essentialsql.com/recursive-ctes-explained/
After dealing mostly with ORMs and programmatic solutions of complex DB queries, this kata seemed confusing, but once solved, it's quite fascinating.

These articles helped me to resolve this kata:
https://www.citusdata.com/blog/2018/05/15/fun-with-sql-recursive-ctes/
http://blog.timothyandrew.net/blog/2013/06/24/recursive-postgres-queries/

Because the object is not just to have the number in the left wing be larger than the equivalent number in the right wing, but also to be as close as possible. So in your example [79, 54, 35, 19, 25, 35] is incorrect because 79 - 35 is larger than 79 - 54, or to put it another way, the largest number in the array should always be on the left outermost, and the second largest should always be on the right outermost, and so on and so forth until you get to the minimum in the middle.