Were it the Couier I played vs the Lone Wanderer I played, it'd be a tossup. My Courier (Thomas) was dammed good in a fight, but was a combat-armored, marksman-carbine using skirmisher. My Lone wanderer (Yelena) is a power armor clad engine of destruction with an enhanced laser rifle and a shocksword. Both attempt to talk before opening fire, but Yelena is markedly more ruthless (as Garza found out in Taft Tunnels the hard way.)

Both are hard fighting professional types, so it'd come down to who screwed up first.

Depends on how the courier is levelled compared to the Lone wanderer and vice versa. I played my courier and Lone wanderer very similarly, so I'd imagine they would fight to a stalemate and be forced to call it quits.