1 3pin fan (or pump) can connect to a 4pin header.
On that board, there is a pump or fan header at the bottom of the board - not going to be a convenient spot for an AIO pump, or fan.
I would connect:
1. pump to the CPU_Fan header
AND
2. Run a 4pin splitter from your AIO fans to CPU_Opt
OR
2. Connect one AIO fan to CPU_Opt and the other to Sys_Fan1 at the top left of the board.