Are Ibn Ishaq & Ibn Kathir Reliable?

Islamophobic Christians are fond of quoting stories from books written by historians like Ibn Ishaq & Ibn Kathir without realizing that Muslims don't consideer these stories sahih (=authentic). In both Islam & Christianity, the religious sources of information are divided into two categories: (i) Sahih or Canonical sources (ii) Apocryphal or Non-canonical sources. Will Christians accept any claim made by a source that they consider apocryphal? For example, Would Christians accept a claim about Jesus made by Jewish Talmud? No, Christians will not.

Once an Islamophobic Christian on YouTube quoted a fabricated story about Prophet Mohamed taken from one of the books of historian Ibn Ishaq. Do you know what my reply was to that Islamophobic Christian? I told him that I would consider accepting the fabricated story about Prophet Mohamed IF he accepts the claim of Talmud about Jesus that "Jesus is in hell, being boiled in hot excrement." (Gittin 57a). Do you know how that Christian responded to my proposed mutual agreement? That Christian got mad at me and started swearing at me and my Prophet like a teen. Who knows maybe he was indeed a teen.