Ther're 3 Musha Gaeshi attached to base 6PS Province. Actual PS is 12?
Musha Gaeshi
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Ther're 3 Musha Gaeshi attached to base 6PS Province. Actual PS is 12?
Yes, each Musha Gaeshi will provide a +2 bonus due to the presence of two other Fortifications (assuming there are no other Fortifications on that province).