I know, and I completely agree with you. Those two could destroy the Perfect Susanoo if they wanted to, more likely than not with ease even. However, if I don't take into account Canon feats only, this thread becomes a mess as to what people should be able to do based on what people said they were able to do. If I take into account their top destructive solo feat, the cutting of the Shinju...well, Naruto's own lava Rasenshuriken sliced through what could be argued to be a far more powerful Shinju, (Seeing as it was still living) and I myself would be doubtful to see that destroying a PS.
In that case, yeah, you're right. That explosion is the biggest non-bijuu influenced one in the manga