For my part, understanding Erf warlord psychology is framed mostly by
this strip. In it, Parson rummages through the Gobwin Knob library. Libraries are created full-form in each city. This is where Parson went to learn the "rules" of Erfworld, but the books contain histories, crests, and scores. Very little on the mechanics.
This indicates to me that Erfworld actively discourages warlords from thinking outside the box. Warlords and nobles don't get lessons in physics. They get history lessons. They conceive strategies base don what has happened before, not based on what people have never done. They're not even taught to anticipate what hasn't been done, which is why they are always surprised when someone does something new.
Cleverness for an Erfer is not doing something new, but doing something old in an unexpected way. Moreover, Erfers don't extrapolate. Everybody is always surprised by novelties. nobody expected the volcano exploit. But once it happened, people just put it into the list of things GK can do. They can explode volcanoes. But to an Erfer that does not mean that they can also conquer cities off-turn.
Vanna used Kingworld to end a turn. That was surprising. But nobody now assumes that Parson can prematurely end a turn. All people did was throw "prematurely end a turn" into the tool box of stuff that can be done with Vanna (linked with Charlie's Arkendish, for those who figured out his involvement). If it were known GK had a turnamancer, they'd worry. But they don't so nobody is concerned.
Even the cleverest of Erfers don't think outside the box. Jack practiced with Parson for dozens of turns. The only plan he could devise was a variation on a stunt that Parson developed in one of their simulations. He didn't invent anything new. He was simply the only one who saw the novelty that Parson had invented.
It seems pretty clear to me that Erfworlders are uniformly uncreative, and that is an intentional design function of Erfworld. The Titans designed the world to discourage people from testing the rules and as a result, Parson has a distinct advantage. So far, the only people who have shown any propensity to test limits are Parson, Charlie, Stanley(!) and Marie. Parson isn't from here. I suspect Charlie has a unique origin too -- or his creativity is being caused by the Titans through the Arkendish. Stanley and Marie each had one spark of creativity. Stanley somehow devised the eyebooks through a trimancer link. Even Wanda remarked that
it was the shrewdest thing he's ever done. And Marie came up with the Summon Perfect Warlord spell. I cannot imagine that Stanley came up with the eyebooks on his own. I am guessing he was influenced through the Arkenhammer by the Titans. And Marie gets all her info from Predictamancy, which appears to be a direct phone line to Fate (and Fate seems to be just another word for the Titans' will).
So, no, I don't see Tramennis holding any idiot ball... except that all Erfworlders ware saddled with the exact same idiot ball -- the complete inability to imagine things nobody has done before.
Parson doesn't "cheat". He invents, he tests, he theorizes. He is Erfworld's only actual scientist.
So I don't see Tramennis as being an idiot, no more than anybody else. He doesn't foresee Parson's exploits because he cannot even conceive of exploits, even after being told of them. No Erfworlder can. He may appear to be an idiot from our perspective, because we don't suffer Erfworlder limitations. He's doing the best he can, but he is no match for Parson, not because Tramennis is an idiot, but because Tramennis, like all Erfworlders, has a horrible blind spot and they don't even know it.