In the retro handheld community there’s a big split between those who prefer left stick on top, and those who want dpad on top. In all cases it’s going to be uncomfortable because of the lack of full sized grips as well as the vertical alignment of the buttons - the diagonal positioning of sticks and buttons on modern controllers is crucial for their comfort and ergonomics.

Stick on top is slightly more popular (it’s like a 60/40 split), but I’m in the dpad on top camp. Without proper grips, devices like these are going to be uncomfortable no matter where the sticks are. But with dpad on top, at least dpad-centric, fighting, and arcade games can be comfortable to play without needing added grips.