Question about Anker PowerCore

That depends on the power bank. Depending on the model, it varies how much power is output in each case. In principle, a USB-C connection should provide the higher power. The question should rather be what kind of devices you want to charge with it.

The Anker PowerCore 26800 mAh has two micro USB ports for charging the powerbank itself and three USB ports that can output a maximum of 3A. However, when all ports are used simultaneously, the maximum power of the powerbank is limited to a total of 6A (i.e. 2A per port when fully occupied).