Trey better than smokey cr LOOOOOOOOOOOOOL. My guess is you don't own one or either of them.
As for the second sentence you wrote, I'm not sure what you're talking about. Are you talking about Cyan? She's 7 power at level 3, level 2 she's 4 power. And damage= opp damage isn't that great in elo because people won't just let you copy their high damager, and if they do, they're most likely trying to win with it. Piranas isn't that great in the damage department
Generally speaking D=DO cards are too shaky to be used properly. And excluding Shizawa, they're not that great against Soa cards. It's a decent alternative, but usually among the first ones to be replaced after you no longer carry cards like Gran Vista.
Trey is just bad. Too weak base stats aren't saved by the +4 pillz.
Smokey Cr is similar, but he just does the job better. He's elo banned because he was pretty much unstopable back in his days.
If you're wondering about the cost. Trey is down because of the Duel mode. Smokey Cr is up, because he's a Cr.