I like Aquaman a lot and he's no slouch. Honestly I prefer him to Namor, but historically speaking Namors always been stronger and more durable. This is a dude that imo clearly has an edge over the likes of Ben Grim and Ironman. Whereas Aquaman always struck me as more of a idtier warrior till Geoff Johns started pushing him in Brightest Day and the New 52.
I'd give Aquaman better control of aquatic creatures and better swimming and leadership skills (because lets face it Namors a bad king) but in terms of raw strength and durability I can't say Ive seen anything that puts Aquaman above Namor.
Look maybe I'm wrong because I don't read as much Marvel as I use to, but why has Namor's stock fallen so much?