The "clicking" device is not really the bottleneck in 3D design. Some people prefer normal computer mouses (high DPI), a 3D mouse (maps to 3D more directly) or touch (intuitive) but whatever.

The crucial part is key presses, all 3D software I've ever encountered can only be used in a efficient manner with intense shortcut using. On an iPad, that's hard, u either sacrifice a lot of screen space for non-physical keys, or use and external keyboard, at which point a laptop/desktop is better; especially with the second key element of smooth 3D editing in mind: GPU and CPU.