It's true that it fails a lot but at a 30% chance when being hit and while hitting it is successful enough to make a battle very one sided. The clown is spitting out ranged damage at 195 attack speed so he's landing multiple hits per second which makes this 30% chance a big deal and if he's being hit then the opponents quick hits will also trigger this 30% chance as well. To add more, if the clown is using any sort of reflect damage gear then each reflected piece of damage also has a 30% chance of triggering the Tarot because it is technically considered damage ouput via the Clown.
So to put this simply he's attacking with a 30% chance of Tarot, reflecting with a 30% chance of Tarot, and being attacked at a 30% chance at Tarot. The 30% may seem like a small percent chance but given our high attack speed and hits per second are so high it is pretty much as sure thing that you're going to be spammed with Tarot while fighting a clown.
Coma isn't the only crippling Tarot effect. The Clown is also zaping your sp, killing you attack power, breaking shields/helmets, stone cursing, and removing buffs/dispelling. I simply do not see how it is fair for the class to be able to automatically cast these status effects at such a rate.
If you think that my suggested changes are too harsh I can respect that but please provide more specific alternatives.
Honestly, I would have preferred it Clowns if had received a Valkyrie Guitar that boosted their damage/hp/sp a bit rather than a bow that can do all the fighting for the user.
Would really like to hear from more people. Keep the comments coming guys I appreciate it.