To get this thread back on track, here are some strategies that a friend and I have used to solo or duo most of Reisenjima's T1s. NQ Abjuration gear was our starting point, filled in my more Reisenjima gear as we got it.
Sang Buaya, Crom Dubh, Zduhac: I won't waste my time repeating what everyone's said: SCH. Sang Buaya is a very easy SCH solo. Crom Dubh is slightly harder, Noiahonto can kill Amchuchu or August if you get unlucky, but addition of a PLD/RUN/PUP would make it an easy duo. Zduhac can get very dangerous below 25%. We mostly killed it with Bolster GEO + Tabula SCH to make sure it died fast, probably not the best strategy if you really want to spam this.
Kabandha: Honestly one of the simplest NMs. I figure probably just about anything with a hate grabbing tool and 50 MDT/PDT can tank this, and then any DD can kill it. We did it RUN + BST. Add more DDs as needed. Just make sure the tank keeps their back turned.
Mauve-wristed Gomberry: We did it SCH + BLM + August + Amchuchu + healer trusts. BLM opens with -aja to stagger by killing all the shadows, then SCH SC + MB. Not a big threat, most important thing is killing the shadows. BLU/BST/BLM can all probably do it easily enough.
Taelmoth the Diremaw: Hits really really hard, so we went with PUP tank + BST DD. Full Azure Lore SC + MB sometimes put puppet into red HP, but not really a threat if you Repair during the middle of the SC. It seemed to wipe buffs every time the BST pulled hate with a Ready, but not when the puppet pulled hate with Provoke or the BST Ready'd without pulling hate. Uncertain if this is a real characteristic of the NM, or just an unusual coincidence however. In any event probably any good DD can substitute for the BST.
Oryx: Long, slow, boring fight. Would probably be faster if our DD jobs were better. Did it PUP + BLU once, then switched to RUN + BLU and it was slightly faster. Breaking the horn didn't seem terribly common, even while spamming Chant (BLU) or Vorpal (RUN). Pretty much any tank can tank this, though PLD is probably best just because Chant > RUN or PUP's options
Selkit: This is by far where our strategy differs from most. We attempted the "lock it into Hell Scissors" strategy, but had poor success rates. Eventually we settled on PUP tank + NIN, with the explicit strategy of lowering our WS rates. As long as you don't WS more than once every 5 or so seconds, it won't Hell Scissors, allowing hate to maintain on the puppet. Care should be taken because the poison it gives is dangerous and temp items to heal the pet might be needed if it decides to spam poison faster than Maintenance/Repair's recast. This is a very slow fight using this strategy, but it gave us 100% success rate. Any decent DD could sub in for the NIN.
Belphegor: Like Zduhac, never really attempted it without 1hr. Full credit to Trulusia on the PUP forums for inspiring me to go out there and kill it with Overdrive. Shijin Spiral to open up Bonecrusher, makes Light. If you plan on doing this I suggest waiting until you have 20/20 in Overdrive JP to really guarantee victory. Poison Potions don't hurt to avoid Sleepga too.
Never needed to try Dazzling Dolores, and have yet to have success with Kist (or try Sabotender duo at all). I realize that a lot of these strategies are slower or rely upon 1hrs that limit their ability to be spammed, but I still think these methods are worth noting.