If one book states that the nuns of Kildare worshipped one God to the exclusion of all others, and another book says that they only pretended to do so, then both authors are being intellectually dishonest, to the extent that they are making flat declarations about things they have no hard evidence about.

If one author states that such-and-such suggests that the nuns may have worshipped more than one god, and the other author says that there is no reason to believe that was the case, then perhaps you can take what they are saying at face value.