Please. Khan was a lame-o threat in both of his appearances. He only got as far as he did because Kirk acted like an idiot in both instances.
It's the perfect example of an actor elevating something on paper that's sub-par. A not bad idea that needed another rough draft to iron out issues and/or ranged character actor to make what's on paper shine. With Montalban they scores. With most actors of the era, "Space Seed" would not be remembered as much, nor picked up on for a film years later...
It was Montalban's acting that took a semi-generic heavy given a free ride by Kirk (twice) into something far more memorable. Granted, some dialogue about Khan's origins and how "
We will do well in your century" are compelling on paper as a sci-fi idea being executed (and Ricardo clearly understood the material, a less-attentive actor would just say "we" with incorrect or without any emphasis), but Ricardo could give even the most banal piece of dialogue some mannerisms and charisma to embrace and behold. He was a first rate actor, making a good character great and ripe for reuse thanks to Nicholas Mayer sitting through all 79 episodes to get a feel for Trek as well as brainstorming an idea for II.
Otherwise, yeah, the old trope of "Let's let the villain win by uncharacteristically dumbing down the hero", aka "
Weslification"(tm), was on display. Unlike Wesley Crusher's instances where the adults are dumbed down, Ricardo and Shatner and crew are on the top of their game and it shows, literally. That and there'd be no story to build up if Kirk gave Khan merely the 23rd century equivalents of "Readers' Digest" and "Federation News and Worlds Report" magazines... Yawnaroonie.
Now if Khan figured out how to hack a system, that would be stupid because none of us would have a clue if teleported 300 years into the future. However, and conceptually, Khan still could use his charisma - which he had, starting with McGivers (A surname with a cheap in-joke if there ever was one, why not go the extra light year and script it as "McReadilyGivesIns" instead? On wait, this is 1966 and not 2016 where sledgehammers need not be subtle anymore, which The Simpsons predicted in 1993 via a Halloween episode joke), but he easily could have won over others in the 23rd century to build an army from within. That would have been even more compelling than the few lines of dialogue Khan was given. Especially with Ricardo's sublime delivery. Ricardo made him iconic, there's no way that's going to be topped. If there is, let me know the store as I want to go to aisle seven and purchase 100 bottled containing lightning that was free range captured.
But I digress, the story opted to use what amounts to sexism as she's taken in by his sugar the same way I don't fall in lust with a computer built in 1968, when there were more compelling ways -- only this time it's not a bunch of spores in paradise but psychological influence. "Space Seed" is good but it could have been "great". Even as part of a fortified breakfast too with the orange juice and bacon and eggs and toast... Mmmm, "Khan Flakes"... sorry for the corny joke, I did have to milk it...
