HID Mode is running via USB Connection; can be used with Traktor or SDJ (think RB uses this as well);
Lan Connection is only required for Rekordbox Link, so that you can browse your music from your MBP and throw it on the CDJs as well as from one CDJ to another;
You cannot connect both CDJs to your computer unless you are using some kind of hub which is connected with you MBP.
If you want to get things done quickly, best would be if you have 2 or even 4 mirror usb devices, so that you can use the USB Function on the CDJs, that would be my suggestion. Could you please explain why you need the Link function in the club?