For the record:
Any lawful leader (regardless of degree of lawfulness) should be able to liberate a city whose alignment is 67-100.
Any neutral (regardless of degree) leader should be able to liberate a city whose alignment is 34-66.
Any chaotic (regardless of degree) leader should be able to liberate a city whose alignment is 1-33.
Edit: It's possible that having unit alignments closer to the Morale of a town may boost your Chaos Frame more when you liberate.
You could also be like me and not give a crap about it your first time through!







