The title says it all:

How many of you play without the Order/Destruction distinction? While I personally consider this to be one of the most offensive developments of Warhammer canon, I understand its accessibility for a newcomer to the universe. I also understand the mechanical reasons it's in play for Diskwars, limiting the army combinations for the sake of balance. I certainly don't criticize Diskwars for taking this approach, but I think there's a great potential for "fluffy" armies to come out of the dissolution of this barrier. I can see this as a fun House Rule to implement- If you remove the faction limitations, you must define why your army is composed the way it is.

During my Warhammer days, I ran a Von Carstein/Empire army, and am more than excited to be able to recreate this in Diskwars.

So my question is: What are some mechanically "broken" combinations that could be made if these borders were crossed? What are ways to avoid/ combat them?

I think one of the main reasons they have the order/destruction factions is for tournament play. It makes it so opposing sides could never bring the same units to the game because if they did it could get quite confusing trying to remember what units belonged to which player when the scrums started happening. Maybe I wrong though. Does any one know if order vs order or destruction vs destruction is allowed in tournaments?

If you want to mix any faction you want though I see no harm in this. I don't know of any broken combos that could come up but If you find some they would be easy enough to ban in future games.

Does any one know if order vs order or destruction vs destruction is allowed in tournaments?

We don't know because we don't have tournament rules yet. Since Diskwars has been added to the official list of Organized Play titles (by virtue of the fact that game night kits are available for retailers to order), we can assume that competitive rules will be announced soon.

I think there are two ways this could go - the first modeled after X-Wing, which specifically allows for "mirror matches" with the same factions facing off against each other. However, you point out quite astutely that this would be difficult because identical units belonging to different players would be hard to distinguish on the board.

The second scenario could be that a player is required to bring two armies, one Order and one Destruction, and a match consists of two games. You'd play your Order against the opponent's Destruction, and then vice-versa. This follows the tournament format for the Netrunner and Star Wars card games.

Or maybe they'll come up with something completely different.