Strikes me Brian has spent the series choreographing to please the judges. And the judges have NOT helped him sort out a weakness in Ali's expression of latin. They've made a few comments about her latin missing something and not being as strong as her ballroom, but their scores have rarely reflected that. So long as he went out and choregraphed steps rather than performance, he was still going to be getting 9's and finding themselves in a safe place on the board. Now we get down to the business end, it's all a little too late. If the judges wanted to be helping Ali, who they clearly like, on at least one or more of her latins earlier in the run they should have been giving her 7's and 8's and a serious kick up the backside that couldn't be ignored by Brian. He'd have had to do something about it, or try to do something about it.
Personally, I don't think it would make much difference. I don't think pulling on the mask to do a 'character' in dance is the same as actually unleashing a part of your character that's actually there but just not showing properly yet. I agree with sofakat, some things are just there or not. But Brian should have at least tried to make her find that 'in' her.
Now, anyway, he's got no choice in the matter. Choreographing for the judges is too late. If we make the assumption Chris wins the public vote, Ali and Ricky's positions with the judges are irrelevant. Who comes top with the public is through ... so he needs to choreograph for the TV screens and the audiences sitting on sofas at home, not the the judges' desk.