I'd say just mathematically scorch is gonna be better if you're actually translating that damage into something, like dragons or plates or pushing people out of lane. Try looking at peoples HP at important moments and thinking "would them being 80hp lower make a big difference here."
I think anywhere below plat elo though, gathering will ALWAYS be better, since the first 15-20 minutes don't matter as much (unless you're hyper snowballing ~10% of games)