Excuse me for asking, but wouldn't it be easier to buy a diagnostics tool so you can read out what coil is wrong?
I have no knowledge of repairing a Clio as I'm looking to buy one now, but i do own a Smart Roadster Brabus and a Mercedes diagnostics tool. There I can read out all the error codes and also get tips on how to fix a problem.
It might be illegal to discuss this in some forums, but I don't say you have to buy a China copy Renault diagnostics to find out what the problem is.