Yep, Phoenix, you've hit my team's weakness right on. Prediction, aka, skill, is what will destroy the synergy of the team, and possibly cause a loss.
I'll tell you what though, if I lose to the two examples you pointed out, which are great ones btw, due to out-prediction, I lost because I deserved to lose, not because of a weakness to the team. Those are losses I happily accept.
I also built the team around that factor of losing due to the skill of my opponent, and not his team. An offensive team based on switching is exactly that type of team.
As your cb Tar, let me think. I would probably switch Lucario or Swampert in, and depending on the attack/damage, I would work from there. If I happen to lose to pursuit, well, that's a risk I run by putting scarf on Gengar, and there is nothing to do there.