To determine if your character's cut-out is sufficient, consider the animation requirements. If you plan to animate the character looking at the daggers and breathing, ensure that the head, arms, and torso are separate to allow for smooth movement. For an attack animation, separating the legs from the hips can provide more flexibility and control, especially if the legs need to move independently. As mentioned in the context, separating parts that will overlap or require independent movement is beneficial. If you find that certain movements are restricted, you can always adjust and separate more parts during the animation process.

radoonha Whether the separation is sufficient or not depends on the required movements, so it's really hard to say for sure. It's common to realize after trying it out that you should have separated it more, or that you didn't need to separate it at all.

The following is purely speculative, so I can't say for sure if it will apply in your case, but for example, you haven't separated the upper and lower arms, and if this character needs to bend its arms, that might not work well. While meshes can bend to some extent, if you're aiming for a more curved bend like in the mix-and-match example, rather than maintaining the stiffness of the arm while only changing the direction at the elbow, you'll need to separate the parts.
Also, if the character closes their legs or crosses their right leg in front of their left leg, the right and left legs should be separated. You can control the overlap to some extent by the order of the bones bound to the mesh, but compared to separating the images in advance, this may require an unnecessary number of vertices, so it is easier to handle if you separate them.

The following article explaining Erika's division method and the Spine Tips video series on division should be helpful. Please check them out!:
Blog: How to cut your assets for animation

Misaki 其实我想了解现在是否有AI可以辅助这样的工作流？每次拆图整理素材都会花费我大量的时间做前期准备，我直觉上认为AI可以在这方面有所帮助，因为大部分都是比较枯燥又没技术含量的操作。

林汤圆 We do not officially offer an AI-powered workflow for cutting out images, though some users may have experimented with such methods.

Regarding the opinion that technical skills are not required, I believe this is not accurate. Deciding which parts of an image need to be separated actually requires knowledge, as well as the skills necessary to create animations in Spine. Therefore, this is indeed a task that demands expertise.

When cutting out images in Photoshop, it is often recommended to use the “Generative Fill” feature, which is one of Photoshop’s AI-based tools. In that sense, AI is already being incorporated into such workflows.

For the time being, the most efficient approach would be to have someone with a clear understanding of the intended animation determine how to divide the image, and then use a feature like Generative Fill to reconstruct the hidden parts with the help of AI.