Is It a Bad Sign if a Church Says the Bible Is Inerrant “in the Original Manuscripts”?

Questions about whether it’s a bad sign when a church’s statement of faith says they believe the Bible is inerrant “in the original manuscripts,” how the Gospel of Mark can be inerrant if someone else added 16:9–20, and whether the Gospels were meant to be complementary.

• Is it a red flag when a church’s statement of faith says they believe the Bible is inerrant “in the original manuscripts”?
• How can we say the Gospel of Mark is the inerrant Word of God if someone added 16:9–20 into it?
• Were the Gospels meant to be complementary? Did the writers intend for us to harmonize them?