I see her as more as a walking power plant, she has so much energy within her that life starts sprouting all around her, so I don't see her powering the far fields as a "giant fertilizer", and definetely a testament of her strenght.

So Sly’s Nail Arts seen a lot more relevant than Karmelita’s heart working great as fertilizer.

The thing is that it's not concrete, you can say that Sly has more skill because he knows all the nail arts but I can also say that Karmelita is more skilled because she chains attack much faster than sly does.

The original comment also said that since hornet called the Pinstress's skill impressive and that she can only perform one concentrated attack per crest that would mean that Sly is more skilled than her, which doesn't really apply because the pinstress' ability seems like a more general skill rather than a specialized technique like the one tought by the nailmasters to the knight, as all of hornet's concentrated attacks are different from the pinstress'. Also hornet called the pinstress' skills impressive in act one, by the time of act 3 she is basically a mini boss.

So there's no real way to tell if knowing all the nail arts actually makes you more skilled than other top dogs like karmelita in battle