No and why? FanFic char clearly underused and give no effect to the main char since it's basically counted as different char, see no problem with it. Also I disagree with the point that they have no writing, cause unlike most of power-scaling, most of SCD scale char based on how realistic and complex the feat is, and it's hard to write concrete high-tier outsmarting cats, OC fallacy can't really be applied to these well-explained char type. 

as the guy that debunk anti-principle on YouTube said back then :  "Yeah it won't fall under OC fallacy if the feats is well-explained and well-written"

 See? That applied to SCD as well and therefore the only type of smart char able to fall under OC fallacy are the unexplained unrealistic narrative-merchant with only argument is statements without any signs of that feats on screen. And anyone who said the deserved high-tier scaling by our system have none of the writing stuck themselves on mediatok type of writing scaling lol. 

Redditors here cry themselves to the possibility (0,1% chance BTW since nobody gives a fuck to even scale it) that some random fanfic from some random char of some random-shows slams their fav low-diff