There were some objectively terrible Akron teams prior to Dambrot coming to Akron. That was before my time though. I would imagine the defense was worse on some of those single digit win teams.
I do think it's lazy to just look at points allowed as the sole measure of a defense. Like your mentioned pace can inflate the numbers. I still think outside of Groce's 1st season this is probably his worst defensive team.
Like you, I don't necessarily think it's all effort. They just often try to trap and then are slow in rotating. Not having a rim protector certainly plays a part, but I feel that would be something we could overcome if we boxed out better and defended the 3-point line better.