"The fact these companies will have been audited in the same way .."

Have they? Are you sure? The Huawei audit were not a routine audit. According to Wired it was done by the special British "Huawei Cyber Security Evaluation Centre". I can't find any evidence the UK National Cyber Security Centre has done the same with Cisco or HP.

am judging this and drawing my own conclusions, but I don't feel they are ill informed (nor do I think yours are)

The difference between us is that I definitely think MY conclusions are ill informed. Hope someone who knows what they're talking about can chime in