What's "significantly", and how long have you had the phone? It takes a bit of time for the kernel to "learn" your usage, and battery capacity may not be fully developed if the battery is really new, so if the phone is only a few days old I'd not worry yet.
Otherwise, dunno. The phones aren't identical inside (and you've not said which versions of each you have/had, Exynos vs Snapdragon may make a little difference), but from reviews I've read I'd expect their endurance to be broadly similar. There may be some aspect of your usage that strains one more than the other, but it's hard to guess from here.