Honestly, I don't think my chances are very good. My teams are not built for the Showdown metagame. They're built for games where:
1. You see your opponent's team before you choose your leads
2. All Pokémon levels are scaled to 50 (no Lvl 1 Smeargles)
3. Sleep clause is in effect
...etc., etc. These may not seem like a big deal, but the first one especially makes a huge difference.
I'm like you also. My teams aren't really suited for the rules. I'm really trying to think of a team I can come up with, breed, figure out the counters for, and work in Platinum moves. All dealing with a deadline. I don't know why they had Sleep Clause in JAA and not VGS.