Would nerfing Jhin's base 10% MS to 4% on a crit be a good idea?

10% + 4% bonus AS movement speed for 2 seconds on top of 20% MS from stormrazor for .75 seconds which guaranties him a crit in many situations is making Jhin basically impossible to keep up with even for sticky champions. You have to hit him with a decently long CC to get a chance at holding him in place so he can't actually run away.

So would it be out of the question to nerf the base 10% movement speed. Say it was 4% + 4% bonus AS for 2 seconds.

That would still be useful but not make him able to so easily get away from danger.