You should make it fine, except for:

Horrific immigration queue - quite unlikely to take so long.

Something going wrong with the transfer from North terminal to South terminal where the train departs - also quite unlikely to take so long.

Ticket queue at the train station - if you can buy your ticket in advance, it should help though, because the manned ticket counters often have a big queue.

I *think* you should be OK with 53 minutes from ETA to the train departure. Of course, there is a risk that your flight is delayed, then it could well be a problem.