The only "operative" of Section 31 that we know of is Sloane. The other two "operatives" that were seen were in the holodeck with Sloane when Bashir penetrated the ruse. They could have been fictional, too, to put Bashir off of attacking Sloane.
The only evidence of Section 31's entire existence is Sloane and his word, which isn't trustworthy. Bashir and Adm. Ross both believed it existed, but again, only Sloane was seen acting as an official representative of this agency.
Frankly, I'm pretty sure Section 31 was nothing more than an elaborate delusion of Sloane's, and that it "died" with him. Alternatively, it was a front for official SF Intelligence actions and operations, with the fictional Section 31 giving Starfleet plausible deniability in all failed operations.