If you were running the lights in series, then yes, at best a 12VDC power supply would run 4 LEDs at best.
However, when running the LEDs in parallel with a 12VDC supply, you are actually putting 12VDC across each LED, which is why you end up needing at least one resistor in the circuit somewhere (assuming you are using all the same LED's) to bring the voltage across each LED to 3.2V (or whatever they require).
Would be the same for your X-wing Dio. One 12VDC PS would be more than enough to run what you need.
Basically if wired in series, you are starting with 12VDC, everytime a LED is introduced into the circuit, it is robbing 3.2V from the 12V, (and if one goes out, they all go out, because the circuit is broken).
In the circuit above, if we had a 9VDC PS (battery), and 3, 3.2V LEDs (lightbulbs), you are dropping 3V every time the voltage goes through one of the lights.
In a parallel circuit if you have the same 9VDC PS and the same 3, 3.2V LEDs, you are actually providing 9VDC to each LED (which is where the resistor comes in, to reduce the voltage going to each LED to 3.2V)
Now instead of dropping voltage across each LED, you are dropping current, but there is no need to worry really about running out of current, as each LED requires very little current to operate, and a 12VDC PS will have loads of current, just looking at 2 I have close by, one has 1Amp, the other is 1.5Amps. Most 3.2V LEDs are about 20mA, which means if you had 1Amp on the PS, then theoretically you could run 50 LEDs before needing to step up the PS.
1 Amp = 1000 mA
1000mA / 20mA for each LED = 50 LEDs
So a 12VDC, 1.5Amp PS, would run you 75 LEDs
Clear as mud?? LOL
