Wow, what a great question!  I love that you're engaging with the charge to deacons and have a desire to faithfully live into that calling! 

A good starting place may be found in a resource created by Diaconal Ministries of Canada, it's called  Guidelines for Benevolence.  It's a helpful tool to work through as a deacon team, to get a sense about who you feel called to serve, what your community may need, and how you as a team are equipped to serve.  Having a good idea about who/what God is calling your team to, is part of the discernment process, and may provide you with a starting point as you "weigh the needs".

I'd love to hear thoughts from other deacons on how their deacon boards/teams handle this!