What tools will you use if you are promoted as a manager of a particular area and you just recently join the company, and you know that you will meet many people struggling for the position?
I have written about this problem on the site already, in this post
And there are also some relevant points here
Many of these points apply, perhaps these other people are not suitably qualified for the job, in which case they should have come to terms with that.
Get everyone you can on your side, firstly by being polite and courteous to them, and listening to their opinions and suggestions. You may opt not to action whatever they say, but let them know that you are aware of their skills and experience, and together you make a great team.
But you are correct when you anticipate that they may not be best disposed to you, and perhaps will not be willing to give you their full cooperation.
Remember that you got the position because management believed you were the best candidates. Now you need to prove that is the case.
All your interpersonal skills and judgement will be called upon. Behave professionally, don’t challenge people on this, treat everyone with respect, and demonstrate your ability with the results you achieve.
But you are right to tread carefully. Be aware that there may be vindictive staff who could withhold information you need, or provide misinformation. Try to identify them, treat carefully the information they provide, keep your wits about you!!
You may need to balance all of that with stamping your authority on the role and your team.