I haven't seen anything that extreme, but almost every time someone switches a party member in a Youtube vid I can't help but think "Wait, why the hell are they putting her there!?" (i.e. Minoriko in slot 2 against a boss with fire/ice attacks that frequently hit the first two slots).
I'm thinking I'll have to be the guy that tries to use Chen, , Sakuya, and and tries to spam Flight of Itaden and with 100% attack and speed buffs, because I'm honestly disappointed I haven't seen that lineup yet. :V
Aya is a better speed buffer than sakuya, even for buffing the whole party. aya can buff all 4 slots with her single cast (and spend less sp doing so) in the time sakuya can use lunar clock. In addition, when you switch someone out, aya only has to buff that one person, Sakuya has to do the entire party buff again .=P.
Orin's cat walk is bad, like.. really bad, even when fully buffed it's only about as good as chen's unbuffed. As for chen, not exactly a good combo with keine, because chen can buff herself better than keine can buff her.
Play whatever team you like for fun, I'm just saying that the reason why you haven't seen that lineup isn't really because "nobody thought about it" as much as it being kinda counter-productive in general.
As for your earlier comments regarding
. The former has good mnd growth regardless of level, but a nuker she is not. Her spells and her mag growth are intentionally gimp IMO because of the death effects, and delay effects (which are completely unique to her btw). I personally am using her on my 2nd playthru, and I was hoping that despite her mediocre mag growth (and her bad level growth), that her final spell would own due to its AMAZING spell formula (seriously, it's almost master spark good). But as it turns out, it's really only about equally powerful as other particularly strong nukes, which isn't really good enough since it costs a FREAKIN ARM AND LEG.
The second character is even worse at nuking. However she has a heal, and she has excellent tanking stats. Don't really use her as a nuker, or a healer (her heal is just too slow to rely on as a steady form of recovery), use her as a secondary tank IMO (slot 2 tank, you can try 1 I guess but that might be pretty risky). I personally like to use Remi as a slot two tank, but sometimes I need to switch her out, so then you know who might be a good temporary replacement.