Why a Tribal was not automatically better for the Dutch

Would the Dutch Navy in 1940 have been better off with Tribal-class destroyers instead of the Gerard Callenburgh class?

Possibly, but the Dutch were a small navy trying to obtain as much capability as their economy could support, and the Gerard Callenburgh design served that need well.

A Tribal-class destroyer could have served some Dutch requirements in 1940, but individual ship power was only part of the decision. The Royal Netherlands Navy had to obtain as much capability as possible from a smaller national and naval budget. The Gerard Callenburgh design served that constraint well. Importing a more powerful foreign class would not automatically have been the better procurement choice for a smaller navy.