separate vector of rec devs by area

[k-doering-NOAA]

Imported from redmine, Issue #68522 Opened by @RickMethot on 2019-09-12 Status when imported: New

When there are multiple areas, it is cumbersome to have SS create a main rec dev and then to have time-varying devs used to partition that into area-specific devs

A sleaker alternative would apply the partition to the expected value to get an expected value for each area, then to let each area have a vector of devs. This would create completely uncorrelated devs among the areas, so might not be ideal for all situations.

A similar approach could be used to partition total recruitment by settlement time, but for this the uncorrelated approach seems not good.