It seems that a solution for awarding badges automatically based on cohort membership will take some development time, thus I suggest the following short-term solution:

1. Once MDLSITE-2081 is fixed and we have a PHM cohort, obtain a list of PHM user IDs.
2. Make use of Aparup's special script (previously used in MDLSITE-2754) and award PHM 2014 badges as a one-off job.

Then for the rest of the year, as there won't be many new PHMs (only a few each month) I can award the badges manually (after checking that Matt's MDLSITE-2625 hack is still in force or after the fix for MDL-42965 is backported).