J5 is latest. When i am confused, i choose the latest release!. Because E5 is already ~8 months old, as you know that how quickly the resale value drops for out of date stuff.
But do confirm that its snapdragon 410 inside it. Sometimes, Samsung use Spreadtrum SoC too. Like, Core Prime 3G has Spreadtrum SoC and 4G variant has Snapdragon 410. I used both of them and differences are noticeable.
P8 lite has above average battery timings, so Samsung is preferred IMHO.