Audino's actually a very solid Pokemon for early-mid game thanks to it getting Secret Power and all. I used one in a Black Nuzlocke, and I was pretty impressed with it (even shedding a few tears when it died to a crit from a Boldore, iirc). Granted, it doesn't get its true love (Grass Knot~) until post-game, but I'm perfectly willing to put it in Low. Considering you can find one of these little healers in any rustling Grass in the game...
Cottonee's actually really solid. The only thing it doesn't have that Lilligant has is Quiver Dance. Instead, he gets stuff like Giga Drain and Leech Seed, which is perfectly acceptable for in-game use (especially since it has a late-game gym it trashes). Mid Tier
Onix really kinda...you can actually get it before Burgh in the Relic Chamber place, but it has a pitiful 35 Base Attack and can't take special hits at all. It works against Elesa and Burgh, but everything else just destroys it Low