Ok, then we can agree on that. My point was that the Chart shouldn't be used to justify Tau and Chaos uniting in EC on any meaningful level because it was silly to use from a lore-standpoint. Gameplay wise, repaint your units and go crazy.
I agree. I don't want alliances of any sort in this game. This particular alliance would indeed make next to no sense, Chaos simply wouldn't give a shit about the Tau. I find the idea of Chaos allying with anything besides daemons or traitor guard bizarre, though.
To explain: What I've been hearing is that the Chart covers possible units for different factions: Tau can fight for Chaos rarely but use the Tau codex rules still. IG fight for Chaos but use the IG codex still, etc. Even if they wouldn't be called IG from a lore standpoint, gameplay wise they'd still use a similar codex. And the reason that the 'Nids are all red is because there's no way a 'Nid would fight for a non Hive-Mind faction. If that's what the Chart is saying, then it's less wonky than I thought. Saying it's possible for some Tau to join Chaos is different than Tau and Chaos are allies of convenience, or Eldar and Dark Eldar are Battle Brothers.
Basically they're tiers of likelihood. Battle brothers are factions actively willing to ally, so IG and SM for instance. Allies of convenience are just that, they might team up if it suited their purposes. Allies of desperation would only team up if absolutely necessary (the game includes a rule about distrust for this one, it isn't suggesting they're necessarily even willing allies). Then there's ''come the apocalypse'' which is the the never gonna happen under any circumstance. So yea, it's a coverall and always refers to races by their codex entries, for ease of understanding about which race they mean, and because that's where the unit's rules are. So it's possible for IG to ally Chaos, because they become traitors. Equally it's possible (even if..strange) for a traitor IG commander to have a squad or two of Chaos marines to order about (which, in essence, would be Chaos allying with IG).
It still seems wonky to me, because according to the Codex, the Sisters of Battle are less likely to team up with the Black Templars than they are with the Eldar, which makes absolutely no sense. Why on earth would a Sister of Battle be less likely to align with a HUMAN than they would with a XENOS.
I doubt we will see any alliance until the Tau arrive and people start pushing for an alliance with the Eldar. Pacts of Non Agression,fragile and temporary ones,however,now that i expect to see,especially if the population pool is correct.
I agree, alliances are fragile at best and most likely impossible in a large scale unless you have small faction leaders making pacts with hostile territories around them for a small time frame. Most likely all we are going to see is a consent of "Oi, those bastards over there are really OP right now, let's all attack them and then when they are all smashed and dying, we can return to beating the shit of each other." or the "I'm just going to pretend your forces were here and I suggest you do the same thing for now."
Like I said earlier, parts of it are a bit meh. Though, one could argue for using the SM ally entry for BT now.