That Speer article is a hot mess! They're really saying is shot placement is key, not bullet design. As long as you penetrate deep enough in the right spot, you're GTG! Speer just undid their marketing for all their premium ammo. (I say this as a guy who has .45 ACP GD in my primary carry pistol)
The cartridge box image is of 380/25/32 Auto boxes stacked.
FTA: "The best modern, controlled-expansion bullets pushed at consistent velocities hit those critical depths regardless of the specific cartridge."
vs
FTA: " an expanding 380 Auto bullet will never penetrate as deep as a comparably built 45 Auto bullet fired through the same barriers"
I've seen no evidence of ballistic gel testing that shows reliable .25ACP & .32ACP GD satisfying FBI standards for minimal penetration, even for unexpanded rounds. If they expand, then you can include .380ACP rounds in the failure to reliably meet minimal penetration standards. If they say unexpanded penetration counts, then I guess they're supporting those that say to use FMJ in those calibers, no need for the expensive GD or other premium HP ammo.
Buy the biggest caliber you can shoot accurately and proficiently, then find the best ammo for that caliber. An expanding HP is not the best ammo for anything below .380, and even for .380, only a very small # of options are good there (not GD).