Usually I would say more the merrier with exchanges, but in this case I agree with you. Only reason to use dinky exchanges is if a coin can't initially get on either Bittrex or Polo. Strange as it sounds to say this, Poloniex is one of the big boys now, so guess that should be the main goal to start with.

I haven't kept track of  the Chinese exchanges, but ideally the coin would get on one of those too (and obviously not Bter).