for some reason “strict of procedures” sounds wrong while “strict of a procedure” sounds and feels just fine and natural. In both cases, it’s followed by a comparison (i.e. “as they did in …”).
Is this just because I so rarely here “strict of” followed by a plural, or is the phrasing actually different with a plural noun?
NOTE: I’m a big fan of the quote “English is the result of Norman men-at-arms attempting to pick up Saxon barmaids and is no more legitimate than any of the other results” so I don’t about proper grammar unless something sounds wrong or is intolerably ambiguous.
Both sound wrong to me, and, indeed, I can’t really guess what either phrase might mean. “Strict” is an adjective. I do not think “adjective of noun” is ever a correct construction in English. Do you mean “strictness”?
A possible phrase is “strictest of procedures”. The form “[superlative adjective] of [plural noun]” is normal English, e.g., “It was the best of times, it was the worst of times.”
Sorry, I do not think either or those are correct. The first could be fixed (well, made acceptable, though not elegant) by removing the “of”; the second needs more work. Maybe “These are not such strict procedures as the SOP specifies,” but even that seems poor. “These procedures are not as strict as the SOP requires,” would be better.
That seems like improper grammar to me, although I have heard people include the “of” in colloquial speech.
“Didn’t have as strict procedures as they do today” would (I think) be okay, but still more awkward than “didn’t have procedures as strict as they do today.”