The LedControl initialisation you cite appears to specify only one digit. (Mind you, I am not familiar with it anyway. )
Actually with the code I posted, I just define the pin numbers (the first three numbers) and the last, fourth number, you define how many MAX7219 chips you have connected in a daisy chain.
Then you use a command like lc.setDigit(address, digit, value, decimalPoint) control each digit from each chip.
So it's not just a single digit initialization.