That article doesn't apply to t1 to t2 transfers.

You will need to walk around 1.5 km in total:
-arrival gate to immigration
-immigration to t2 departures lobby
-(check in for second flight)
-departure lobby to exit border control and security
-security to gate

Since the cut off for check in (international) is t-60 minutes for most airlines, you would need to do the bulk of the above in under 5 minutes. Even if you're a track star, your inbound flight is on time, and you breeze through immigration unencumbered, that's not going to happen.