Yes you can connect two motors to a single MM430.
The VSD cannot then provide I2t protection for the motors, a thermistor in each motor would be useful for this.
The I2t must be provided by individual thermal overloads, one for each motor.
Watch out for the total cable length, the maximum for the cable will be about 60 Meters, it is easy to get a very long cable length when doing this. To get the cable length add the cable for both motors together.
Both motors will have to be started at the same time so they both benefit from the ram up time.