I don't know.
They seem to have a lot more "engineer" abilities then "assault" ones on their grid.
We already have assault pioneers in game.
Its OKW starting unit.
It would be inconsistent to have 2 completely different units with the same name.
"Assault" engineers clearly don't need five men then, if they're primarily being built to provide engineering services. Other engineer units don't arrive with five men by default, so it's pretty inconsistent.
No, those are called "Sturmpioneers". "Angriff" is "Assault", "Sturm" is "Storm".