BCH chain will have a small hash rate? I thought the powers of Jihan Wu and some of the other Chinese miners are riding under his banner in support of the fork?
But it will be way lower than what BTC segwit will have after the split. BTC supporters can easily attack this minor chain and like OP have speculated BCC might struggle to survive from spam attacks.
Why would the Bitcoin supporters attack the BCH chain if it is better for them to leave it alone and hold or sell their free BCH coins? I believe this is where game theory applies. What is more profitable for you and the everyone else, to spam and attack BCH or leave it be and let them develop on their own?