There actually was once a fourth Disciple of the Land class planned for the original version of FFXIV called 'Shepherd' that seems to have been intended to be similar to your 'Trapper' idea, and they even had an empty, unused Guildhall in Falcon's Nest in the Coerthas Western Highlands, sadly however it was never implemented and exactly how it worked is all conjecture (it's guildhall was not included in Falcon's Nest's rebuilding in Heavensward so all we can assume is that SE has officially abandoned the class.

Which is a shame as it would be an interesting concept - there was even a class icon for it floating around online (where exactly it was discovered I have no idea, I found it on a site that has long since disappeared sadly):



Shepherd. Never forget.