The motor power is the same as one coil's rating because with microstepping the coils are in sinusoidal
quadrature and the power doesn't vary with step state. Most NEMA17 are about 4--5W, this one is a whopping 8W so it has high-temperature insulation and magnets I think. Anyway it will run really hot
at 2.5A, consider running it at 2A instead.
If each motor takes 8W stationary, thats 32W, so allowing for motor driver losses thats about 50W needed
so 2A at 24V. For any speed though, the power taken will rise, so lets say 3A or more is reasonable. The
extra power overcomes back-EMF, ie its mechanical power delivered to the load, so it will matter how
much load there is as well as speed - exact calculations are not easy...
BTW if those motor drivers aren't discrete-MOSFET designs the losses will be a LOT more, does
anyone know if its discrete MOSFETs? The difference is a discrete MOSFET driver will run cool, not