Unfortunately, the command "control faction" does not work in the game console. It can only be executed from the background script.
There is a script inside this mod that uses this command to allow players to control more than one faction at same time (named "hot seat script"). You may take a look to that script and to modify it so it stops after several turns. This way you could grow the economy of several factions for some turns and then, to continue playing with one single faction.
For example (inside background_script.txt):
Code:
monitor_event FactionTurnStart FactionType britons
and I_TurnNumber <= 20
console_command control britons
snap_strat_camera 0, 156
zoom_strat_camera 0.8
while I_LocalFaction egypt
end_while
snap_strat_camera 0, 156
zoom_strat_camera 0.8
call_object_shortcut strat_ui save_stratmap
inhibit_camera_input true
disable_entire_ui
hide_ui
end_monitor
monitor_event FactionTurnStart FactionType egypt
and I_TurnNumber <= 20
console_command control egypt
snap_strat_camera 0, 156
zoom_strat_camera 0.8
while I_LocalFaction britons
end_while
snap_strat_camera 0, 156
zoom_strat_camera 0.8
call_object_shortcut strat_ui save_stratmap
inhibit_camera_input true
disable_entire_ui
hide_ui
end_monitor