This seems like an ideal fit: Matz has a more contact-oriented approach, so he will likely appreciate the Cardinals' good defense. As a LHP, he complements their other four starters nicely. The term and money seems absolutely okay to me.
Matz is no ace by any means, but I wonder why the Blue Jays did not issue a QO for him. Even if he had accepted it and failed to pitch like he did this year, Toronto might have overpaid a bit - which seems a negligible amount given the chances the Blue Jays refused to take.
Gruß,
BSHH