Use same custom field across multiple custom tables Merged

I would like to have a team custom field associated with a Master feature for estimates and a team custom field on a release to indicate capacity on a release.  i would like these custom fields (team custom fields) to be the same custom field, so i can run a report showing capacity and Master Feature estimation in the same team column.  we are currently in estimation phase, so would be nice to have asap, but could wait a month.