Interesting - I climbed the Aonachs via the WH route in 2015 - I'd only done about 50 Munros, and I'm definitely a cautious and careful type - but I don't remember it being an issue.
Vaguely remember it as a steep sandyish descent in a well-worn deep trough-like path down the mountain side.
My resounding memories of that walk was the thick mist and arguing over direction finding on Aonach Beag.
We sat for a while on Beag and the walking partner decided we would go back the way we had come.
2 fell runners then appeared out of the clag and we joined forces with them to make our way over to Mor and then down the steep descent and back to the start.
Perhaps we were concentrating so much on keeping up with them that we didn't notice the state of the path