Hello! You've improved this team a lot, so I thought I'd help.
Note: You didn't provide natures, abilities, or items.
Pokemon need items.
You're really so adamant about not replacing Aggron? It has 2 4x weaknesses and can't take adantage of Sturdy because it's so slow. I think Aggron is a bad Pokemon, even for NU. No offense.
Also, Leavanny is pretty good, but only on a sun team.
Magmortar is a great Pokemon, you're just using it the wrong way. It's a born Special attacker.
Magmortar @ Life Orb/Choice Specs
Timid Nature (+Spe, -Atk)/Modest Nature (+SpAtk, -Atk)
EVs: 4 HP/252 SpAtk/252 Spe
Also, Skarmory doesn't really support your team very well, considering the number of Steel-types you have.
Could I see your team as it is envisioned after you finish reading this post?
Also, assuming this is your team:
You have a HUGE weakness to Ground, along with a fairly large one to Water, and STAB Fighting and Fire attacks aren't good for your team. So, basically, watch out for a team with both Infernape and Swampert/Gastrodon.
Also (and I'm sorry if this sounds rude), I thought you were hopeless when I saw your first post, but evidently you've made incredible strides. Good job!