Plugable hub can handle more units (as of the power) but there is limited area around the plugs ... need to use extension cord if you want more sticks.
IMO 25W will be enough to run 4 units at decent clock around 4Mh. You need to test it, see the HW error rate and adjust accordingly.
Thank you very much for taking the time to respond. I have ordered a used unit (Pluggable USB3-HUB7-81X) for $17.
I have mocked it up and it will have no problems fitting 4 moonlanders in terms of physical space. So we will see about the volts/watts/amps.
Mockup below, will report back with more details in the coming week.
https://i.imgur.com/naxUtGA.jpg