Flew NRT-DTW-LAS on a MR back in May with a tight connection like yours. Before I landed, DL protected me and rebooked me on the next flight since we departed NRT late and I would have misconnected per MCT.

DTW customs was quick for me - ~10 mins. However, I had no checked bags. I found the biggest bottleneck to be security screening - there were just a lot of people there. I would estimate about 20-30 mins in a regular security line. With CLEAR, I got through security very quickly though and made the original flight.