forlorn hope wrote:
I have an enterprise that is being extorted by a 2 strength regular troop card. Can I drive it off with a 3 strength regular troop card, or do I need to use troops from one of the other 3 factions?
As mentioned under 'Redeploy' in the glossary, there is no distinction between being defeated (by opposing troops) or 'relieved' (by allied troops). In both cases, the displaced troops lose whatever marginal loyalty they had with you. 'Loyalty' is an inappropriate term here, it is a purely pragmatic allegiance with whoever provides for the troop's supplies.
The living rules contain an optional rule (listed in the 'Retreat' glossary entry) that distinguishes between being defeated or relieved, allowing the latter to Retreat: "Optional: troops that are replaced by other troops of the same color are NOT defeated, only “relieved”. Such troops CAN be retreated."
A reminder that if you wish access to the googledocs Living Rules for Pax Porfiriana, in which you can download or make suggestions or add comments, drop a line to firstname.lastname@example.org.