I'll go with my girl P!nk because she has no equal when it comes to her touring power and TTAL has been a massive success WW.
It's hard to tell with Miley because she's only just joined them - obviously she was Hollywood Records' biggest earner. She's off to a good start with her two singles though and hopefully the album sales will be strong too. I feel like a tour of hers would do very well WW (The Gypsy Heart tour was a big success coming off a flop era) but I'm not sure about a US tour or if she has the pull for a stadium tour there. The US is weird about her.
X made more money than the rest with mainly just Feel This Moment. Minimal effort, and low expense cost leads to a great revenue. No wonder she's been on that label the longest.