I missed an opportunity to purchase *recycled* 3″ eps, i may now have a chance to get 3″ “recycled* Deckmate, will this be ok for my exterior insulation. 

Note: i have replaced the stud bay insulation, it is now R14 Rockwool, i omitted the 6 mil on the walls but kept it on the ceiling, and installed the new drywall as “airtight” drywall. 
Also thinking i need to install ? 3/8 (price is in the budget, 1/2″ would probably be best but lots of$$)  plywood over the exterior fiber board.  I can attach a wrb with more ease, and also have more attachment area for the deckmate.

Would like to hear you thoughts.  

Thanks again for all your help.