Okay, here is the setup:
We want to record 30 channels of a concert with DIGICheck. Interface(s) will be two Fireface UC. So we need two additional cards feeding their channels per ADAT too those RMEs. My Question is: What way would work regarding syncing all those units without using wordclock? A/D 1 gives his clock to RME 1, this transmits it via ADAT cabel to RME 2 and RME 2 delivers A/D 2 the clock via ADAT too. I have no experience with bigger (> 2 units) digital setups and at the moment I have also no BNC cabels. Is there anything special to consider? Would it work without a problem or a can there be something unpredictable happen?

With best regards
El Duderino