So, how do we distribute Uncommons and Commons over 80 packs? Well, pretty simple: 80 packs á 3 commons gives us space for 60 commons (4-of); 78 packs á 2 Uncommons gives us 52 Uncommons (3-of), the remaining 4 slots fill up a 61st Common. That's not all the Uncommons though - the Starter box deck(s) for the expansion means that there will be some more Commons and Uncommons in the starter box. The average starter deck has 4 commons and 2 Uncommons in it. Boros (or Rakdos?) Crew will 100% be one of the starter decks, the other one would either be Fabricate or Energy - if there is a second one.

Uncommons: Kaladesh has 11 Uncommons per colour, 10 multicolour uncommons (1 for each colour pair), 2 lands and 13 colourless Uncommons. I believe that the multicoloured cycle will be in Duels entirely, leaving us with 42 Uncommon slots left - 7 for each colour and 7 for lands/colourless.

Commons: Kaladesh has 16 Commons in each colour and 21 colourless Commons (no multicolour/land commons); which would likely mean 10 Commons in each colour and 11 colourless; plus/minus the ones in the starter box for the deck.