Phrase: you can do your little number on them

[Toygirl2]

I was watching the DVD of the Apprentice.
(U know, the TV show where one of the members from the losing team will be fired by Donald Trump each week.) I don't understand one of the remarks made by Donald Trump in the boardroom.

In the boardroom scene, Donald is talking to one team.
Donald: "I sort of hope you win. I'm not supposed to do that. But I hope you win so you can do your little number on them".

What does "you can do your little number on them" in the context?

please advise.

[Mister Micawber]

Perform some characteristic ability or routine, usually an antagonistic one. It is impossible to be more precise without knowing much more about the group and their previous performance.
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Native English teacher at Mister Micawber's

[Toygirl2]

In the previous episode, Donald asked Team A ( where Tim and Nicole are a couple ) to send the weakest member to the opposing team. Then Team A sent Nicole to team B. For that Nicole got really pissed at Tim becoz Tim didn't defend for his gf or try to stop her from being sent away. Nicole also got pissed at Team A for sending her away as she thinks it's disloyal to her. Then the two teams are competing against each other in a business game.

After the game, Donald will fire a member from the losing team. And the winning team can help Donald to pick which losing team member is gonna be fired. Before the result of which one is the winning team is revealed. Donald talked to Nicole and made that remark.

Donald said, "I sort of hope you win. I'm not supposed to do that. But I hope you win so you can do your little number on them".

I look up the meaning of " do a little number on sb" on the Internet.
do a number on someone or something
Sl. to damage or harm someone or something. e.g. The teacher did a number on the whole class by giving them a pop quiz. Tom did a number on Mary when he went out with Ann.

Does "do a number on sb" = " do your number on sb" in this context?

So, regarding Donald Trump's remark. Does he mean " I hope you win so you can did something to hurt your old team"?

[Mister Micawber]

Sorry, I guess it's a situation where I'd have to watch the episode, but yes, there is probably 'hurt' involved.
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Native English teacher at Mister Micawber's

[Toygirl2]

Mister Micawber, thx for your suggestion.

So, does "I could do a number on him "means the same as " I could do my number on him?"

Which saying is more common in oral English?

[Mister Micawber]

'My number' is one specific to me; 'a number' is any of several, and not necessarily mine.
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Native English teacher at Mister Micawber's