I've been reading a fair bit on modern methods of construction (MMC), and find it quite puzzling how it can work structurally.

It seems strange that MMC 'pods' can fit into traditional construction techniques.

What are your thoughts on MMC structurally?

Welcome BCD
Which method ?
As Modern Methods of Construction (MMC) cover a wide range of materials and degrees of assembly on site (building) from panelised walling systems to completely fitted out flats and Hotel rooms Built in factories and delivered to site and hoisted in to place, then just fit external cladding (modern or traditional) and hook up the services.
The common practice with flats and hotels is to just use bathroom pods which are slid or lifted in as each floor is built and these are non structural in the case ive seen.
Other panelised systems are like timber framed systems of structural panels.

Here is a cold rolled steel based framed system going up in Sheffield, on an In-situ concrete ground floor. Its for flats
http://i205.photobucket.com/albums/bb264/Daveb_design/City%20centre/2008_0207sheffield0041-T.jpg