D&D 5E Playing Next without a Grid - Fighting Style: Protection

[Li Shenron]

For those that are using 'theatre of mind' rather than a battle grid in Next, how do you deal with the Fighter Class's: Fighting Style - Protection.

We're having this issue exactly in a 5e PbP game right now...

The Fighter has said in favor of which allies he prefers to use Protection, so I'm taking this into account if they get attacked. If they move away, the Fighter can't use it, but I'll let him use it in favor of anyone else nearby...

Anyway, since it's "theatre of the mind", distances and positions are supposed to be loose, thus it's more of a matter of "are we all in melee together, or split in groups?".