One common mistake in reasoning is to assume that just because two doctrines are similar, one must therefore have come from the other. For example, JWs and Moslems share certain beliefs: they each reject the Trinity, the divinity of Jesus, and an ordained priesthood. In spite of these similarities, only someone ignorant of history would assume JWs draw their beliefs from Moslems.

If two things, A and B, are similar, there could be at least four different reasons why:

To demonstrate that one belief comes from another, it's not enough just to show similarities between the two. You have to rule out other reasons that may account for the similarities and you have to account for essential differences. JWs don't do either of these when it comes to the Trinity.