How to limit current to LEDs
No, that's the right way to do it. Each LED having it's own ballast/series current limiting resistor, sized in Ohms and Wattage to fit the desired forward current of the LED and the Voltage source.

The "wrong" way to do it would be with only 1 resistor for multiple LEDs in parallel.

But if you are going with 3 Watt leds (That's 940mA at 3.2V, not 600mA.), then a resistor is not a good choice. You should look into constant current sources. Using a resistor would require power resistors that can handle high wattage. At 5V source, that's 1.8V * .94 Amps = 1.62 Watts. A 2 Watt resistor is needed. For each led. That's a lot of wasted power, 65% efficiency.