That ranking is indeed bizarre. Were the voters predominantly fujoshi? Mikleo wasn't even the best character in Zestiria; I'd say that was Edna.
If you asked me which Tales characters I quite liked, I'd say (in no particular order), Jade, Raine, Yuri, Luke, Velvet, Arche, Rita, Raven, Edna, Tear, Magilou.* That's a pretty bad mismatch with the survey; I only picked two of the top ten, and at least a couple of mine aren't even in the top thirty.
Sorey and Asbel were rather generic, and wouldn't place in my top twenty.
*List may not be complete. My memory ain't that good. I think I'm missing a ninja or two.