It sort-of is. The hero is a former big game hunter who decides to take on really big game - people and, more exactly, a dictator.
As someone who is permanently banging on about Rogue Male, I probably ought to say why I like it so much.
Firstly, it does an enormous amount with very little. There are only two or three real characters, most of the action is very low-key, and, as you say, a lot of the story takes place in the narrator's mind. It's powerful not because of the body count (although lots of bits get chipped off the hero, in various ways) but because we see into the hero's head so well and understand what's at stake. His own mental change, as he starts to admit what his reasons are for his mission, is well-presented and follows his changes of circumstances.
Secondly, it's one of the few books that touches on a particular streak in the British psyche back then (and quite possibly now) that is usually only dealt with these days in parody. Our hero is a nice, friendly chap - and a unrelenting killer. His calmness actually makes him rather frightening: I find the scene where he assesses his wounds after being tortured and thrown off a cliff really quite unpleasant, because it is so restrained. He's like the Terminator with social skills. I can easily imagine him ending up in the Special Operations Executive or Auxiliary Units.
Thirdly, there's the land. It really is a book about being on and in the landscape and making use of it. Household really does sound as if he knows what he's talking about. Like a few bits of King Solomon's Mines, it almost feels quite mystic as the hero considers the land around him. Household seems to have worked out the practicalities of the story well: there isn't a sense of things working out for the narrator because he is the hero.
Fourthly, that bit at the end. Jason Bourne blowing up a house with a toaster is nothing compared to the narrator's disposal of his arch-enemy. I can't say much more because it would spoil it, but it's ingenious and gross in equal measure.
The only other Household book I've read was A Rough Shoot, a long time ago, which I thought was weaker and more conventional. I gather that he wrote more thrillers, including a sequel where the Rogue goes to the continent and blows most of it up, and a rather odd novel set in a jungle involving, IIRC, giant otters.
