Good day,
Yes, I think you've run into the fact that schematron was never completely reintegrated into Amara 2. I had always intended to do so, but the demand was more around porting other parts of the code base. Because I know Amara 1 and Amara 2 so well I was able to scratch my own itch when I needed schematron by basically hacking across the code bases, but I never got around to making it usable for everyone else.
Gosh, I hate to say it, but the best bet is to use Amara 1.x for Schematron. It's implementation is comprehensive and well tested. I've sort of given up making promises about Amara's future, but I can say that the need for easily-deployed schematron has reached my work situation, which increases the chances that I'll be able to get to that as Amara 3 comes along.
Thanks.
--Uche