Right you are. I know the passage. I'll have to go dig it up and have a look at it. See if it might be interpreted in some other way.
I doubt you could take it in another way without really stretching the realm of believability. The passage in question is from Black Colossus, page 168 in
The Coming of Conan the Cimmerian:
". . .they brought harness to replace Conan's chain-mail -- gorget, sollerets, cuirass, pauldrons, jambes, cuisses, and sallet."
Howard seems quite capable of differentiating between, say, a hoplite style of 'plate' and a late medieval style of 'plate' - most obvious from his use of late medieval inventions like the gorget and cuisses, as well as items like jambes and sollerets.
Sollerets are plate boots - and didn't come into use until the existance of true plate armour (late medieval). Gorgets are throat-guards of plate, also not existing throughout the early medieval period or before. Cuisses are thigh (and sometimes knee) guards of plate associated with full suits only. And jambes is a (now outdated) word for full-piece greaves. These are the only items listed besides the cuirass and -possibly- pauldrons that could be construed as not necessarily pieces of a full suit of plate, and so open to debate. But taken all together, to me it seems fairly obvious that he's describing a plate harness like those worn in the late medieval period.
One -could- make the argument that Howard did not include gardbraces, couters, rerebraces, or poleyns - but I'd say these terms are a bit more obscure and he may have simply either ignored them, not known the words to use, did not feel it was necessary to describe every single piece of armour, or envisioned something like a cross between true plate armour and something that shows off Conan's nifty biceps.
Your interpretation may vary, but mine is that this is clearly a suit of plate armour as we understand the term's relevance to the late medieval period.
