Absolutely right - plus any transfer to T4 is just about the worst possible because of the lack of options due to the location of the terminal. There really, in these circumstances, is no option but to rely on the airside flight connection buses - a landside transfer, which often works well from say T2 to T3 because of generally shorter security queues landside, is too lengthy and convoluted in this case given the available time.

Throw in a potentially long walk from the T3 arrival gate, and it's definitely not something I'd be attempting.