Faction Strength: 4
Faction Summary:
Ability
You start the game with only one Dwelling. You may only place this Dwelling after all the other players have build all of theirs (if necessary, after the Nomads have placed their third one, see setup on page 5). You get 2 Favor tiles instead of 1 whenever you build a Temple or your Sanctuary.
Stronghold
After building the Stronghold, take 1 Action token. As a Special action (once per Action phase), you may take a double-turn. (On this double-turn, take any 2 Actions one after another – passing is also considered an Action.) Use the Action token to keep track of using this Special action.
Faction Overview:
The major issue with the Chaos Magicians is that they are short 1 worker income from the start, and they are also denied the option of two starting points. However, if you upgrade and get Favour Tiles fast enough, this initial disadvantage turns itself around.
Chaos Magician Strategy
In general, you want to both build 1 Dwelling, and also upgrade to a Temple in the first round. Upgrading first turn will give you more income from each of the favour tiles you choose.
Take favour tiles in this order:
1) 4 Power:
2) 1 Power, 1 worker:
3) 2-points per dwelling built:
4) 3-points per Trade Post built OR Points-for-passing with Trading Posts:
OR 
While you NEED an income boost from your first two Favour Tiles, your second two can easily be used for the points boosts. Because you’ll have a priest income for the whole game, the Cult-Action Favour tile isn’t as good as you might think – two priests are usually just as good as this tile, and you need the income more in the early game.
It’s also possible, by burning power for the 7-coin Action Space and getting the 2-worker bonus tile, to upgrade to a Sanctuary in the first turn, assuming that the Round tile gives you points for this.
Grabbing the 3-rank Cult Priests
Since you will have an early Priest income, grab the 3-Point Cult spots on the Cult Track, which hopefully will also give you some income boosts from the Round tile end-of-round bonuses.
First Turn Bonus Tiles
+3pw, +1 shipping (for expanding across a river)
+3pw, +1 worker
+2w, +4 SH/SA Points
+6c (for early Sanctuary upgrade)
Situational Starting Locations:
D-6 or
D-11 or
G-6
The locations for all factions don’t seem to fit the standard map (there is D11 or G6 for red). What maps are you referencing to?
All you say with the field except D6 is not possible, there is no D11 field and the G6 field is a lake for mermaids or swarmlings. The first steps are helpful, but the starting locations are weird. If you could explain me that it would be helpful.
The river on which you can not build is also counted.
Example:
G6 = 1-river, 2-river, 3-river, 4-gray, 5-river, 6-red
Look at the strategy guide for the giants there is an example board with all the numbering there are a few boards being used on website like board game arena, there you would have to come up with the best starting positions yourself