You are correct;
I have had a TS with access to Secret Compartmented Information, Critical Nuclear Weapon Design Information and level One Presidential Access for 21 years and I can count on one hand the times I have been exposed to TS info. Except for the area 51 alien thing but that’s another story.
I think that what’s happening here is that the Washington Post doesn’t understand that there is a specific meaning to the term “Top Secret” - Looking at the WaPo article, I have to wonder if they’re counting everyone from TS/SCI to Secret right down to Confidential clearances in their “854,000” “top secret clearances.”
Considering that they routinely confuse an AR-15 with a machine gun, I wouldn’t be surprised if this is what’s going on here. I’d be stunned if there’s nearly a million people going through a SSBI every three years. How many investigators and polygraphers would that take? That’s nearly 800 people per day!