Here's a fun thought exercise. Are there any situations where you might consider it worth the risk to heal the Unknown Ranger? Sure the idea of putting that murder machine back to full health is attractive but given the low amount of games I've played over the last year I'm having a hard time coming up with a scenario where it'd be worth the risk of killing him out of NWI. Without a cube we're looking at 65% success rate regardless of the tool being a WIP 13 doctor or a medikit against his phys for what seems like much of a gain when he's still just as lethal while in NWI. Has anyone ever pulled off this particular gamble in a game? Wild Bill and Wallace are also worth mentioning but at least the have the benefit of a reroll with their cubes. (I suppose it's an equally valid question to ask of the Vet-Kazak or the Kosmosoldat but my USARF bias is showing.)
No, with only WIP13 and no cube it's just not worth the risk. I'd make an argument for Ariadna having the worst Doctors in the game if it wasn't for the 112 frequently becoming a murder machine with his Shotgun!
YES!!! I personally believe the motorized 112 is one of the most underrated profiles in all of Ariadna. I consider it an almost auto include, especially in USARF. And not for healing stuff but as a turn three active killer/objective grabber. But back on topic. I would consider trying it if you have a linked paramedic. The additional burst on the Medikit and the pass one fail one no longer being a wash makes it at least feasible.
Doctoring him. Never. Way to risky. But I do agree with @McKaptain . A linked medkit would be worth trying once in a while. Odds are extremely good you'll successfully put both shots on him if you still have full link bonuses.
In previous game my Vet kazak paramedic in a three man kazak core lost a wound. He could have self medicated a single dose of that sweet nano-med, but instead managed to convince the other paramedic to administer a double shot.