Yes, 24 byte array for each anode shift register, just like there are 24 bits of cathode shift registers.
When column_count = x, then the xth byte goes out to the anodes and the xth bit of cathode turns on to drive the xth column.
I posted example code for you a couple of times, go re-read some of those with an eye to the above statement.
I'm working on my own 12x8 array, using a different driver approach where 1 is off and 0 is on, I may go to your approach if it doesn't work like I want it to.