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As said, higher inertia means they will not accelerate as fast, but you are converting a mill, so it is not as if you are going to be spinning then up to 1000 RPM anyway.
3Nm motors with 5mm lead...

Nema 34 will have slower acceleration since it's rotor is bigger, causing the moment of inertia to be greater, but clearly the high voltage driver compensates.

Having different drivers on each...