Unsure how you want to Structure this, However Here's my 2 cents on the Matter.
You have Media- Iron Harvest, should add Scythe to that.
Iron Harvest - Factions, Features (Or Game modes), Other stuff we don't exactly know yet
Scythe - Factions (Scythe) [Which Will link to a general factions pages for each group with Scythe and Iron Harvest Sections], Gameplay, Expansions
Factions - [List all the Factions in world as we know them. We can take from Scythe which is most complete and then wait and see what Iron Harvest does with them/uses].
Individual Faction- Iron Harvest and Scythe info in the same. Lore and general information can be communal. List of Heroes for each factions can be listed and linked to their own pages. Iron Harvest on the top and we'll add as we get more information and can link to all the many, many units that'll appear. Scythe section at the bottom discussing the Faction bonuses and differences for each faction. Since that'll be smaller I feel it should go last since it'll change the least and the Wiki is named the Iron harvest 1920+ Wiki so hopefully we'll get many Iron Harvest clicks.
Units should have a template we can add to each one with a Picture, Faction, Health, Cost, Attack, Etc etc etc for Iron harvest and we can slap a small Scythe section at the bottom if they overlap (Heroes and big mechs will since scythe is simpler).
That's all I can brain vomit for now. I don't want to take over or anything. Let me know what you are thinking and I'll alter and start writing up what I can.