The ShackTac Fireteam HUD has been ported over to Arma 3, whee! This mod requires the CBA modset, which can be read about here (it is automatically installed when loading STHUD via PwS).
Watch the video for an example of how this mod functions. Note that the STHUD Usermenu addon is not included yet due to CBA still being ported over to A3 and not having the necessary functionality yet.
If you run into issues with it, please post them to our tracker, here.