Group 2: Snake eye 5/5 is a must, put at least one merit in Loaded deck is a good choice, rest is either fold 4 or fold1+winning streak 3.
Absolutely the standard thinking ^^
I personally used to be 4 Fold, 0 Winning Streak, 1 Loaded Deck for 75COR. I just changed to 1 Fold, 3 Winning Streak, 1 Loaded Deck recently (just put the 3rd Winning Streak merit on last night, in fact).
My biggest reason is that these days I simply never get into the same precise rhythm I once did with 75cap COR activities. Now if I'm in Abyssea it's much more random and I don't have a precise 3-4 roll cycle. I might be a little lazier with timers while just rolling 3 DD rolls, or sticking Chaos + ??? on the DDs and maybe dropping Tactician's or Blitzer's on just myself away from the group. It's just not the same as that feeling I had back in an old style exp/merit party where I could tell just by an internal timer in my brain when to roll that next roll in my cycle exactly when needed.
In dominion ops parties, people are running back and forth so much from the book, or fighting different mobs, so you might miss people more often. Longer buff duration means less chance people are fighting without 2 active rolls because you missed them. For NMs, you might have people running around and not really sticking together (maybe staying back far out of range of AoE until getting TP, then moving in to WS). Nice to do something like stick Tacticians on all the people you can and have an extra 1min active if it's hard to hit them all together the next time.
I suppose multiple fold merit is good if you absolutely need to land a good buff, usually defensive buffs like magus/evokers. But that doesn't happen very often. Unless the XI bouns coming this June is truly amazing, and worth spending extra time and sacrifice all the DPS to go for it, I'll just stay Fold 1/5 for now.
On the flip side, if the XI bonus is truly amazing, Winning Streak merits means you get extra time to take advantage of that bonus every time you do hit an XI. I'd rather be able to Fold less, and enjoy the benefits longer when I get an XI.
Besides, Fold is also limited by Phantom Roll timers (and Random Deal). When you Fold, you're spending a lot of time re-rolling and doubling up. If Random Deal is up you can re-roll immediately, but if it's not (or if it resets a different ability) you also have to wait for PR to be ready to use again.
For Group 1: QD recast 5/5 is a must have, then rest is either PR recast or QD acc depending on how you play.
Honestly, I'd probably drop 5/5 QD Accuracy (how often do you REALLY have QD accuracy issues?) and pair QD Recast with Random Deal merits if RD merits were better than the lame -40 seconds per merit on a 20min JA. Say, -2min per merit making 5/5 Random Deal a 10min recast.