I know Skratch  (youtube CC for RAID)  believes  strongly in HP over defense generally speaking

so I have given more credit to HP over defense since he made that claim in one of his videos

probably does  not answer your question directly though :/  sorry for that

The short answer is "neither". Assuming you're running a non-unkillable team, your goal is to have your team survive long enough that the first person dying is to CB's stun. On UNM, a good 2-key team should last to at least turn 35, preferrably closer to 40, and a 1-key team will need to last to around turn 65 or so.

Defense has an effective soft-cap of 4200, but remember that is AFTER DEF up, which almost every non-unkillable team should be running. With DEF up, that means you need about 2600 DEF. If you also have something like Ally Protect, that number goes down even more.

HP doesn't have a soft-cap, but more than around 45k likely won't translate into you surviving for much longer.

All other stats should go into getting CR to 100%, and then CDMG.

Do poisoners need to be at 100% CR?

"Need"? No. Their priority is getting ACC to around 200. But that shouldn't be a very difficult task. Once that's done, CR to 100% is next, and then CDMG as with everyone else.

Thanks that helped a lot.