We selected Escudo II some years back for an 18.1h mare belonging to someone I knew. She liked the foal so much, she bred back to him the next year. I haven’t seen those fillies for a few years (they moved out of state), so don’t know how they turned out, but the last I heard, they were thinking they were going to finish in the 16.3 - 17h range.
There are some smallish guys on the OHBS/GOV roster that would give you a KWPN register A foal (assuming you plan to stay with KWPN). Some are listed at 16.2h, but they must have been standing on their tippy-toes when they were measured, or their owners “rounded up” when publishing their heights.
Benidetto (16.1-1/2h, Belissimo M / Cordoba)
Dacaprio (16.2h, Davignon I / Caprimond)
DeLuxe (16.2h, De Niro / Andiamo)
Escudo II (16h, Espri / Arkansas)
Pablo (16.1-1/2, Pilot / Matrox)
Rapture R (16.1-3/4, Rotspon / Donnerhall)
Regazzoni (16.1h, Rubinstein I / Werther)
Rodioso (16.1h, Rohdiamant / Furioso II)
Roubaix (16.1-1/2h, Rohdiamant / Lamentos)
Royal Prince (16.1-1/2h, Rohdiamant / Prince Thatch xx)
Sir Gregory (16.2, Sir Donnerhall I / Don Gregory)
Sure Hit (16.2h, Sandro Hit / Furioso II)
One think to consider is how much height is in the stallion’s pedigree. For instance, Sir Gregory is one of the “smaller” 16.2h stallions, but he has a fair amount of height behind him (Sandro Hit, Don Gregory, Donnerhall, etc.)