The swap is definitely possible, there are some people who have done this already here in germany - but it requires serious coding skills to get the oil temp working.
As with every used cluster: you have to clear the cluster to the state "new" - like it left the factory (uninitialised) which is not as easy if you are not familar with electronics (you need additional hardware and reprogram an EEPROM afaik). Otherwise you will at least get the "manipulation point" if your car's mileage is less than the one in the M cluster. Simply swapping is therefore not advisable...

@Qsilver: HIGH cluster without MID/NAV would work without problems: the MID/NAV is only a dumb "display" with some buttons, no further functionality involved - though you will be unable to use some of the HIGH BC functionality and aux heating and ventilation...

Already verified this ages ago on an e39