Hi Au Dio,

Playing the game as the Romans is the set way by CA to unlock the other factions, but you can cut and paste as you show here.

however, you really have to ensure you keep everything in place, and just cut and paste the factions you wish to play and add them to playable from the unlockable section.

Be aware that you've added Roman Senate which along with rebels are really truly 'unplayable' unless you enjoy your game crashing all the time.
I believe there are a few others that are troublesome, so focus all your cut and pastes to the unlockable section.

Oh and copy your file to a safe place before messing with it !!

hope this helps.

And for any moderators passing I really think that a better version of this explaination ( of which there are many ) should be added to the FAQ if its not already as its asked a LOT.