It has always seemed to me that anyone believing in ultimately one God, the father of all Creator of all that is, from the Universe to the smallest microbe, then, just as mankind has many languages, then inevitably any name will be in different languages.
To that extent, then, all religions believing in one God who made everything must by definition believe in the same person.
They may believe different things ABOUT him; that's another matter. Even religions that seemingly believe in a pantheon of different gods, when examined, may express those beliefs as one overall God whose many attributes are expressed in different ways or forms. That is the case with Hinduism. Even in Christianity, God is expressed at times as the ground of our being, very akin to Buddhism, as I understand it.
Christianity is expressed through an understanding of God as Three Persons, for the most part, though some express their understanding differently. Especially Jehovah's-Witness-ism.
For the most part, I find no great difference between my own orthodox Catholic beliefs and those of others whose love for Christ reveals very little difference from me.
If there is one God, then there is one God. He doesn't speak French or English or German or Hebrew or Tagalog; he speaks everything. He is boundless. Eternally the same, now and for ever, but each is dear to him, which isn't a blanket approval for doing anything.