Adding new unit
Something about unit ID
Every unit on map has own special ID, with every call of addNew() method, it will create with next unique unit ID. If you want add specific ID to unit, add optional argument with custom ID addNew(id=397).
Check all class.Unit(blank) attributes and methods
Adding unit to specific player
Creating unit for Player 1
scenario.players[1].units.new()
Creating unit for Gaia Player
scenario.players[0].units.new() # Player 0 = Gaia Player
Unit at positions
scenario.players[1].units.new(x=23, y=5)
For more information about coordinations in scenario, check class.Tiles
Adding Knight or other real unit
Adding specific unit, you have to know unit type ID. For example, in this case, Knight has id type=38.
For list of all unit types, check enums.Units
scenario.plyers[1].units.new(x=23, y=5, type=38)