a stiff clutch pedal doesnt always mean a bad clutch. 9/10 yeah, but my RT had a real stiff clutch when i first got it.
Then the cable snapped (nasty habit on clios, ive had 4 snap on me in total over 2 clios).
When i replaced the cable, i realised that it was routed in the pedal properly. There is a little hook kinda thing on the top of the pedal that the cable has to run through, and the old cable was running over it, instead of through it, which caused it to wear away.
I replaced the cable myself, routed it properly, and now the pedal is a lot easier, more like it should be.