The word you're looking for is "largest" iss, though i agree the set isnt very uesful because it's 80% outclassed by Abra; And I will show you why:
Smoochum has shittier typing, and shit for abilities.
Smoochum has 3 higher stats than abra, HP, Attack, and Special Defense. Attack is obviously useless on a special attacker, so its struck from the list. Since you're running LO, you'll want 0 HP IV's to put smoochum to 19,minimizing recoil (especially important w/ Subs) and abra's minimum is 19, so you can cross HP off the list as well. Lastly, smoochum has 1 more uninvested Spec D than Abra. So its got that.
Move wise; Smoochum does get access to Nasty Plot and STAB Blizzard; both of which abra would looove. And while access to NP does redeem the set a lot; there's not a lot Smoochum can come in on and force out to get its sub up to allow it to NP like ISS said.
Abra is faster, stronger, and doesnt have much worse defenses while still maintaining strong offensive presence and perfect coverage.
Basically: Nasty plot is really all it has over Abra, and while it does provide it with the power to *wreck* teams; getting it up against competent players (like not me) will be a chore, and, while its 17 speed is fast, it's still easily revenged.
Responding to above post: Ferroseed walls the set pretty hard (with its high Spec D and resistance to Psychic) and can break the subs with STAB SE Gyroballs, or STAB bullet seeds (which will probably kill). Jolly Drilbur also his 17 speed, even in hail; so at best you'd be speed tying. I can't really speak for anything else; though croagunk probably wouldnt stay in unless it's faking out (which will hurt like a mother; courtesy of 15 defense)
(01:44:11) +blarajan: stop organizing threesomes in the main chat.