There are more considerations than just lead screws, for instance, look at the spacing between the rails on the gantry. Looking at the narrow Z-axis I'd also bet a packet Hobnobs on it they only use 1 linear bearing on each rail. Same for the long axis, it's not very wide, it's covered hiding who knows what, and while I won't bet a full packet of Hobnobs I'd certainly give you few biscuits and a dunk in my tea if it didn't.

The machine design isn't the best IMO. I'm always suspicious of machines that are covered and don't show under them. Covers hide a multitude of corner cuttings.