It was still a nudge not a broadside at speed
Given the size of the container ship and the time it takes to slow down or change course of such a behemoth, the cargo ship must have already been correcting to starboard when they made contact
My guessing
I’ve seen reports that the major damage was below the waterline. Berthing areas on small ship are below the waterline with the exception of chiefs and officers. The fact the ship lost power even with two separate engine rooms also indicates major damage.
I agree from looking at the damage. If a direct broadside, the mass and inertia of the commercial vessel could have cut the Fitz in half, or enough damage to sink it. Plus, there would have been much more damage to the ACX.