Romeo board and LCD pin assignmet conflict?

#define motorDir 4 // INA motor pin
#define motorSpeed 5 // PWM motor pin

Any reason the motors can not go to pins 2&3?

#define motorDir 2 // INA motor pin
#define motorSpeed 3 // PWM motor pin

Just wondering. Is there a specific frequency you trying to get out of the pin 5 PWM?