Page merging behaviour for tables may seem erratic to a user

Page merging behaviour is different if multiple users are editing a row that existed before they started editing as opposed to a new row they created during their editing session.

Compare the following examples:
Say a page has the following table header only

Two users start editing the page at the same time, they both add a row underneath the header. Both users perceive that they are both editing the first non-header row.
When they save however, both of their rows get integrated without conflict warning

While this behaviour is not inherently problematic, it is inconsistent with behaviour in a situation that a user may perceive as identical

Take a second example
Say the page above had a table header with a blank first row to encourage collaborators to enter data

Two users start editing the page at the same time and they both fill in the blank row provided. Roadrunner saves first. Wylie Coyote saves second and is presented with the conflict warning page.
The behaviours in both scenarios in isolation are acceptable, the inconsistency across both scenarios might confuse users. They might wonder why they get a conflict in the second scenario and not in the first and reason that it is a bug.