edit: I'm still a little confused though. What is the point of developing their own sophisticated risk model when the price of the policy will ultimately depend on Swiss Re's risk model?
Swiss Re reinsures Climate Corp, not any individual policy. So Climate Corp sets the price for each policy and pays out each claim. Swiss Re pays out to Climate Corp if in aggregate all the claims are greater than the price charged.
The policies are reinsured by Swiss RE Corporate Solutions Ltd which also has an A.M. Best rating of "A+" (Superior).
It looks like Swiss Re has a pretty significant global crop insurance business.
http://www.swissre.com/reinsurance/insurers/agriculture/
edit: I'm still a little confused though. What is the point of developing their own sophisticated risk model when the price of the policy will ultimately depend on Swiss Re's risk model?