Well, I've tried playing W2 with my main team being Watchog, Audino, Boldore (haven't had anyone to trade him with), Unfezant, Basculin, and Emolga. I got knocked out a lot by major trainers and my Pokemon kept getting knocked out in long routes or caves (the Chargestone Cave, for example), but it was intensely challenging and kept me on my toes. Yes it's hard, but it's also pretty interesting to use Pokemon that most people wouldn't normally use.
Sadly, they were vastly demolished by the time I faced Drayden, so I began relying on stronger Pokemon in the end. But I'd like to try finishing a game with just these underwhelming Pokemon for a change.