I'm fairly new to the RGB game myself. It has been a process of learning from my mistakes (all the info you need is right in these forums).
Basically, all the fans have to be the same model. So, your ML's wont work with your LL's. At least not in the sense you've been assuming.
Please review Zotty's excellent sticky about RGB set up.
https://forum.corsair.com/v3/showthread.php?t=173880
Hopefully, you can return the single fan ML for another LL so they can sync up.