すうぃっち・ゆあ・すうぱあばいざぁ

No problem of your switch for supervisor.
But you have to consult your present supervisor and try to continue maintaining your present field site.
If your supervisor is willing to accept your switch, I will be your new supervisor without any problem.
You should remember the teaching of Ruth Benedict's monumental work, "Chrysanthemum and Sword," we used to put a premium on the evaluations of one's respectability! According this cultural logic, you have to negotiate softly with present supervisor on this issue.
From Norainu no Kuro,