We need an official list

[Incredible Bulk]

We need a player friendly list of which factions will be the most challenging to play with and which will be the best starter ones.
we need to have in mind, access to rebel settlements that can be taken quickly, income from settlement, miltary power, neighbors ect.

[Torvus]

except that TFON designed the mod that the factions would be equally balanced. All the factions have readily available rebel settlements to take over and the potential to make quite a bit of income quickly. The difficulty comes from the player's playstyle and the faction's rosters.

[Incredible Bulk]

I would think the Pale Knights will not be same easy playing field as lets say the Uruks

[Torvus]

Again, difficulty comes from playstyle. The Pale Knights get tons and tons of powerful units that get free up-keep which makes creating powerful armies easier. As well, there are several nearby rebel settlements for the taking, three IIRC. As for the Uruks, their infantry is powerful, but when they come up against cavalry heavy armies, they get outclassed. The factions are very evenly balanced. The difficulty really does come down to play-style.

[Kaiser Leonidas]

I'd definitely agree with Torvus here. I'd say Thera is one of the best balanced mods so the difficulty of each faction mainly comes down to your own play style. Each faction has its own strengths and weaknesses. I'd agree that the Pale Knights have a kinda tough start between two factions who are very likely to attack you, but you can beat them reasonably easily as your troops are on the whole better, and you can use crusades to your advantage and force them into wars against multiple other factions too.

[Comrade Roboto]

Then maybe a list of each factions strenghts and weaknesses is what you're looking for, bulk?

[Incredible Bulk]

That will work for new users both new to the mod and game. For new users playing mean nothing really since they are just starting out