I've seen others run one pump 2 radiators, so potentially you could. I wouldn't recommend it though.
pump#1 > miner#1 > radiator#1 > pump#2 > miner#2 > radiator#2 > pump#1 > ...
I'm looking for redundancy if 1 pump die the miner can still run. Also, I'm looking to use a larger radiator for multiple miners and I want to know if it's a good idea to run them in series. In the end, I want to do something like this:
pump#1 > miner#1 > pump#2 > miner#2 > badAssRadiator > pump#1 > ...
I know miner#2 will run hotter than miner#1 but in average they should run at the same temperature than having them run side by side with a splitter.
Its not a good idea to run two pumps in series, especially when one has failed. There is a larger syscooling kit designed for 4x C1s, designated as C2.