I am a big fan of Cleary's 3336F (Thiophanate-methyl) because it is a systemic. Mancozeb is contact.
On the US west coast, the anti-fungal spring prophylactic rotation was Heritage, Cleary's 3336F, and Mancozeb - 7-10 days between applications. This worked well for conifers that were staying too wet during the spring rains. Now that I am on the East Coast, I spray Cleary's on my entire garden every spring just as buds are starting to push.