The information on these motors is somewhat limited/variable. They appear to exist in 12V and 24V versions and 100, 120, and 150 W.
12V 100W would have a theoretical full load current of around 8A. In practice I doubt if the efficiency is much better than 75% (maybe worse) so maybe 11A.
A 20A MCB per motor would be appropriate as starting currents will be higher. What sort of controller will you be using?
As you are working at 12V arc supression in the MCB will not be a problem. This generally comes in above 50V.