So Orc gives you potentially 6 Strength + Unbreakable.
Human gives you 5 strength + Adaptive.
Let's assume we will grab Berserker 3 talent for both at some point.
Orc Fighter can get up using Berserker, go broke again and get up using his kin talent, then use Berserker and so on. Two things that can spoil this is: critical injury (which can be countered by Lucky, which can be countered by Executioner) and Coup de Grace. But in the end- you get very sturdy, very tanky (for Forbidden Lands) front line fighter for your party.
Human Fighter can get up using Berserker 3, that is all. However, he can also use his kin talent to be able to perform various other things: Healing, Performance, Stealth, Survival, Marksmanship etc. He won't be as sturdy as Orc, but he can perform a lot different tasks and bring more utility to party.
What race would you prefer as your party Fighter?
It's worth to mention that Unbreakable can be done by party Minstrel with Path of Hymn 1. So maybe if you already have one, it might be worth more to bring Adaptive to the team.