HELLO ANON I HAD NO IDEA PEOPLE WERE SENDING ME RETROSPRINGS. sorry for the late reply! the placements were based mostly on a combination of what genre I think their songs would end up being + my familiarity with the seiyuu as singers. yes there are a couple placements I would change

Oz & Arthur: Oz's seiyuu is one of the ogs of good character songs as far as I'm concerned and I Cannot imagine him doing a bad job. excellent singer, excellent low tone so he wouldn't have the issue of having to push his range somewhere that sounds more strained as some other people on this list would. Arthur's seiyuu can also be quite good. importantly, I think they would probably get a slower, softer song, which would be complimentary to both their voices and play to their seiyuus' singing skillsets

Mithra & Rutile: as I said under the original tweet this could either be incredible or not work at all. I especially like Rutile's seiyuu as a vocalist and have faith his performance would probably sound good no matter what; Mithra's seiyuu is also really talented but I have less of a sense of what he would sound like as Mithra in specific, so I think there's a chance he might lean into sounding bored/flat to a point where it sounds less good from a singing/music standpoint. I also don't know how good their voices would sound /together/, because their ranges and tonal qualities are so different. but the real sticking point is I have no fucking idea what the song would sound like here in terms of genre/tempo/instrumentation. it might be more of a gag song? in which case I probably would find it entertaining but wouldn't want to loop it as music I just like listening to. but I'm technically still leaving it in good because it could just as well be amazing

Shylock & Murr: Murr's seiyuu is more of a newcomer so I'm less familiar with his body of work, but I have heard him sing once and liked it! I am VERY familiar with Shylock's seiyuu and Shylock is exactly in the strikezone where I like him best. by far the most likely sound for this would be something in the jazz/lounge family which I am all about and I have faith the seiyuu could knock it out of the park. I want this in my ears

Chloe & Rustica: I SHOULD probably put this in mid, actually. I think there's a pretty high chance they would get a more playful-sounding song with more talking inserts which goes back to the "not the kind of song I'd want to put on loop" thing again. I think their seiyuu are both good and they would sound good together, though

Riquet & Mitile: I think I put this in mid to be nice. I like Mitile's seiyuu fine as a vocalist, I know Riquet's less well but I think he'd probably sound fine too, and they would probably blend well together, so while I don't think they would be exceptional I don't think there'd be anything to complain about on that front either. but I also think it would be a particular kind of cute twinkly music that I don't really like at all. maybe it would be too mean to call it bad. other people might like it just fine

Brad & Nero: I don't know why I didn't put this in good the first time. it would obviously be rock, I love rock, Bradley's seiyuu is at his absolute best as a singer in this kind of role, and I literally have rock character songs at my disposal to get a pretty close approximation to what Nero would sound like and those songs slap. I would like it. maybe I worried they wouldn't blend well together but I think Nero's seiyuu is some kind of wizard and it would work out

Cain & Owen: this should also go in good. I'm sorry. at the time I made the tierlist I wasn't familiar with Kanbara Daichi's game.

Faust & Lennox: Faust is the one carrying here. I just think Lennox's seiyuu would be too held back by character affect in a way that sounds strained/distracting to my ear. like Oz and Arthur I think they would also get quite a slow song but unlike Oz and Arthur I don't think this would be to the advantage of the seiyuu's strong points

the twins & Figaro: there is simply no earthly way the twins will sound good. I don't even like White's talking voice. that is NOT his natural comfortable range by any stretch of the imagination. Figaro additionally presents an extra layer of difficulty where the song has to somehow accommodate his old man range at the same time as the twins' child range

Shino & Heathcliff: I don't think either of them are very good singers. I'm not even sure if Shino's seiyuu could physically sing while maintaining Shino's character affect