A mini arcade controller is often so small that there is little to no wrist resting space, but the tradeoff is that you get something portable and so on.
The GRAM PRI$M allows you to play Smash and other titles ergonomically with a variety of possible layouts.
The SGF Faust is a mini stickless controller with LED plus a TRS jack for external input sources like foot pedals.
The G series of Haute42 controllers can come in 16, 13, or 12 button editions in order to cater to your needs.
The RaidenBox is a mini all-button controller that is made of acrylic & nylon and is inspired by the Flatbox & Snack Box Micro.
The Steelbox is a mini stickless controller that has 14 buttons and switches, with the jump button being bigger than the rest.
The Paragon is a wooden stickless controller that has its own layout (unless you choose the standard layout).
The Caster Acrylic & Resin Fightstick DIY Enclosure by Raw Super Arcade comes in Vewlix, Noir, all button, and other layouts.
Ultra Arcade is a Brazilian company with a European subsidiary offering all kinds of fighting game controllers, such as the Keyboard Pro XL.