not necessarily. Professional analogue interconnection is all balanced but grounding schemes vary, some installations carry all drains through, others break them, either in the XLR etc or at jackfields or Krone frames.I suspect that the reason that worked is because introducing balanced cables into the equation also breaks earth loops.
I'm afraid I don't get what these cables are for. Standard length is 1m, the longest on offer is 5m. What use is that?