I want to know why...
the creators of Smallville think it's necessary to introduce the Legion of Superheroes. I mean, we get it; we know you already threw canon out the window, that much was evident when you introduced Impulse. Not that bringing in Bart wasn't totally awesome--anything involving Bart is instantly awesome. But you've introduced him, as a teenager, to a barely-twenty-something Clark Kent. And unless he was flat-out lying about his origins (which is possible, given some of the remarks he made), you've changed his backstory, too. The age gap there...well, it just doesn't work. Clark is in his 40's, at least, when he first really meets Impulse. Impulse is Superboy generation. (please don't bring Kon into Smallville. Spare him. D:) Also, the introduction of Doomsday as a main baddie (poor Davis D:) before Clark is even Superman was just kind of weird. But sure! Okay! We get it! You don't like canon! Cool for you!
But of all the heroes you have to bring into it, you choose the LoS? And not only that, but you leave out Brainiac 5? THE ONLY GOOD THING ABOUT THE LEGION? Why, oh why do you have to bring them into it? There are hundreds of other heroes you could bring into it! If you're so desperate for young heroes, hell, give the Green Arrow a Speedy! That'd be awesome! Bring back Impulse! Hell, bring back Super Girl!
Also, if you're going to go through the trouble of bringing in the LoS, why not just give Impulse his original story? Unless, like I mentioned, he was lying to Clark, which would explain his having fake IDs with the names Jay Garrick, Barry Allen and Wally West on them (awesome Bart moment). That'd be cool.
But honestly. LoS? Really? Those are the heroes you really feel like introducing to spice things up? Jeeze.
I'm such a nerd.