about the "pure math", here's what i came up with so far in terms of relationship between angle (0->180) and pulse widths to the two wheel servos:
if(pos<=90)
{
pulse_1=1300;
pulse_2=1300+(40/9)*pos;
}
if(pos>=90)
{
pulse_1=1300+(40/18)*(pos);
pulse_2=1700;
}
right_servo.writeMicroseconds(pulse_1);
left_servo.writeMicroseconds(pulse_2);
delay(20);
PS I'm using the Arduino Servo Library, on an Arduino Uno
HOWEVER, like my original question, the movements would be very rapid and "jerky' because of the constant change in the angle (pos variable) which represents that most open space.