Dear mercato353, thank you for getting in contact with us.
The mDP to HDMI cables you are mentioning are so called ‘type 2’ cables which means they support the HDMI 1.4 features like 4K @ 30Hz support. They are passive though.
For a multi monitor setup with extended displays the requirements are not the same as for an Eyefinity 6 setup. But even for a setup with extended displays we recommend to use at least 2 active mDP to HDMI adapters like our CAC-1153 cable: