SkiParty's Pre-War Tips (Defense Team Setup)
So everyone, after reading and looking over peoples teams I thought that I would create this post. This is to summarize my thoughts into a single place versus cluttering up the alliance chat.
If you have the time, please review the forum post with the attached video. The video is great and shows how important it is to just stay alive. Key notes from this posting and the stuff that pandemic Disease put out.
Stay Alive - Defense Team Setup
It appears as though the balance of power has been heavily shifted to the defense team. In addition to the normal game play, the defense team has a "revenge bar" which pulls 25% of each offence team members HP relatively frequently.
Team AutoPick - Do not let the game autopick any of your teams. This will result in leaving your very frustrated, read on and choose your own team.
Left to right - specials fire off left to right, so ensure that you plan them accordingly. In the picture below, Isarnia is on the far left as her special includes a defense de-buff. So if Isarnia and Sartana are both mana full, the computer will fire off Isarnia's special before Sartana's. If they were in the other order, Sartana would do less damage to the opponents.
Two Healers - According to Pandemic Disease (thanks) your team should consistent of at least two healers. This is to keep everyone alive during the war and let the Arrows do the killing.
Area Of Effect (AOE) - Use players that hit everyone (Isarnia, Quintus, Hu Tao, Li Xiu...) versus snipers (Joon, Sartana...)
Hero Position Matters - Tank still gets hit the most with the Support Positions being the hardest to hit with Tiles.
Color Stacking - Defensive teams don't color stack... putting two or three of one color (especially the same color as the tank) makes you vulnerable to offensive teams color stacking. Wrote up more here.
Player Positioning
Please consider this when setting up the war team (and to a lesser extent a raid defense team).

Tank - Since the offensive team attacks with tiles, the tank takes the brunt of the initial damage. It appears as though the tank should also be a healer as you can't heal them in-be-tween battles. From the advice of other players, don't double stack the color of the tank (e.g. no more red in my team for the picture above).
Flank - To me these are the heroes immediately to the left and right of the tank (if this is not what flank means, let me know). This position gets a lot of incidental tiles, so fast mana attacks are good here (in raids anyways).
Support - These are the players on the very outside of the hero line-up. These are the hardest heroes to hit. This position is the best for Squishy heroes.
So taking all of my advice, I reorganized my team with the lowest defense/hp heroes in the support positions, Viv as tank (hopefully her defense and healing saves my tush) and my snipers as flank.

I will update this post, post my first alliance war.