I'd say looking at some of the Legends that wedges may also be supported draft archetypes.

It looks like there is room in the number cruch for 10 2 color uncommons (of course we already knew UG->merfolk) but there isn't room for common dual lands so I think 3 color will only be weakly supported. Of course, treasure lets you make a splash.

The two gaps in the land crunch could be Evolving Wilds and Unknown Shores.

Also, Unclaimed Territory goes a long way to supporting three-color tribal. I know it's uncommon and not common, but still...

Also card draw. I think card draw is playing heavily in Ixalan merfolk.

So they did spoil an uncommon 2 mana tribal-creature-only mana rock. And a UR uncommon pirate with raid (4 mana 4/3 loot on raid).
So I am not sure that clarifies wth this set is trying to do. Although 3 color shard pirates and dinosaurs looks more likely. Still would like to see some common fixing.

BTW, going out on a limb right now: The set after Dominaria and the new core set will be multicolored-matters. We've visited Zendikar, Innistrad, Kaladesh and Amhokhet since the last multicolored set, with Ixalan and Dominaria (unlikely to be heavily multicolored) waiting in the wings.

You're probably right, I just wish I could believe that theme would have a > 2 year gap rather than being fairly constantly pushed.

a multicolor matters (gold commons? like Ravnica or Alara?) would be VERY strange in a core set.

When I said "the set after Dominaria and the new core set", I meant Dominaria, then core set, THEN multicolored set(s)...i.e. I meant the Fall 2018 set.


Well a 3 1/2 year wait (DoT was Spring 2015 and the set after the core set will be Fall 2018) is a helluvalot better than Ravnica + Shadowmoor + Alara = three multicolored blocks in four years. Also better than RTR + Tarkir = two multicolored blocks in three years.

UW:
WG: Dinos/Toughness matters
RW:
WB: Vamps
UG: Merfolk/+1 counters
GR: Dinos/Enrage
GB:
UB: Treasure
RB: Pirates
UR: Raid (?)

Is that what we have so far? Vehicles might still be an archetype, which would probably be UW or RW at this point.

Maro's design article specifically outlined the 4 tribal factions - 1 Naya (Dinos), 1 Grixis(Pirates), 1 Simic(Merfolk), 1 Orzhov (Vampires)(which was pretty easy to infer from the spoilers), but it's interesting that this was an original design back to Khans. Also that this set got started with "Vampire Pirates!!" not "Dinosaur Pirates!!" which is strange, but hey, WoTC.

I think that GB/RW/UW will not be very well supported at all - but there are probably ~mono color decks splashing the second that are viable. Obviously sealed will be a big mess.

As MaRo and Zenbitz noted, the tribes support every two color pair except Azorius and Golgari.
Golgari is particularly difficult because the two black tribes are the "invaders" and the two green tribes are the "natives"
But there's hints at a Vraska in this block, so that might help the Golgari draft build.
Though it's possible the draft strategy will be two shards and eight guilds. You CAN draft Boros Dinosaurs, FWIW.

Right I forgot boros dinos. Actually I blame fel for leaving it off his chart.

The starting point was was Vampire Conquistadors, not Vampire Pirates.

I guess RW can have a heavy tribal focus for Dinos while GR and GW can focus more on side mechanics of the tribe (Enrage and Toughness), much like RB focuses on the Pirates themselves while UR goes for Raid and UB gets Treasure (I think).

UW I think will focus on Vehicles. Both Vamps (W) and Pirates (U) have ships, and White has been a Vehicle color in the past, while for Blue we already saw a Vehicle tutor that's Blue. Maybe they'll also focus on Equipment.

I think GB will focus on Explore. It makes sense on Black for the Vamps (and we already saw a Black Rare with the mechanic), and Green wants the +1/+1 counters (and we saw some Merfolk that care about them). The mechanic also makes the most sense in Green.

The U/B uncommon is "artifacts matters" as well... but the black card that explores is rare so I wouldn't read that much into it.

Got bored, here's what we are still missing>
Mythic
White ?WW spell(I think it's an enchantment) representing something contorted hit by sunlight(maybe just an object).
Legendary Multicolored dude standing on a ship, probably ?WB I think it might be the vampire admiral

Rare
No white remaining
Blue
Spell with a guy creating a glowing magic surface over his head, reminescent of the magic shield some counterspells depict ?UU
Creature with a small type line(maybe fish, but looks a little humanoid?) ?UU
Black
Instant or sorcery that with a ?B cost, seems to be either a cave or someone's chest/torso in a dim light with some blacks lines around it
Red
Noncreature with a ?RR casting cost that seem to represent a pirate on a ship holding a giant crossbow, it has an ability with activation cost ?RR that seems preceded by raid, yet the typeline seems short for an enchantment, maybe it-s a way to recur it from the grave
?R pirate with an ability that costs ?R
?R raptor like creature with a keyword
Green
A dinosaur costing ?G

Multicolor
A ?RG dinosaur

2 different ships

I'm wondering if the Golgari and/or Azorius draft archetypes (if they exist, still not 100% sure they do) will be mixing Merfolk and Vampires. The way we've outlined it, Pirates and Dinosaurs each appear in three archetypes, while Merfolk and Vampires appear in one each.

The Favorable Winds reprint might be a boon to the Azorius draft archetype.

Well merfolk don't fly so my guess is UW cannot be both merfolk/vampires and "skies". "Skies" is likely the default (and there are some little flying pirates), but it's going to depend on how many wind drakes at common get printed. Similarly BG might end up with a minor graveyard theme (as it often does).