It would be a single debris field if it had been on the bottom - per the press conference, they didn’t make it to the bottom, but they were (relatively) near it. It will probably take computer modeling to figure out how far above the ocean floor they were.
Somewhere it said the debris field was ~1600(?) feet from the Titanic wreckage.
Why go, even in a safe vehicle, if you can’t accurately navigate down beside it?
And, somewhere else, it was said this vessel had previously gone down and could not find the wreckage.
(Yeah, I understand that what’s “said” can be wildly inaccurate)