12 button controllers are how leverless controllers started—since you have four buttons for directional inputs and eight buttons for attack inputs.
Consider the Yume Tanuki if you'd like a small leverless controller that still has some decent height to it.
You should be able to order Akekon Dojo's Shinpuri regular or large case option with 24 or 30 mm buttons, depending on your hand size.
With a conveniently magnetic bottom, the WoodPunch L can come with 16, 15, or 12 buttons infused with Cherry MX Speed Silver switches.
The DoubleSalt is a hitstick with directional buttons that are more slanted than usual, and three of them are smaller than the other buttons.
Ionic Impact is Swiss and offers DIY cases in lever & leverless formats, such as the Ionic and Doric Fightstick Cases.
The Card by Shoebill Gaming can have one or two thumb keys. Its look can also be light wood, dark wood, or custom art.
The Ultra Arcade CNC features an aluminum enclosure by SiTong and can feature premium parts from brands like Sanwa and Cherry.
The FightBox B-Pro is the head honcho of the B series, given that it's got 17 buttons—a good number to conquer tournaments.