Processing order of vertices and fragments in arm gpu

When the ARM GPU processes vertices and fragments, in what order are they distributed and processed? Vertices are in index order? What about fragment? Can we try to control the order of the index on the cpu side to improve the efficiency of the GPU?
For example: Does the optimization of the link below improve the gpu of arm? If there is an improvement, what features of the GPUs they use? github.com/.../meshoptimizer
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