SHOULD Dinar & Dirham be WEIGHED/MEASURED in Grammes?

Had an interesting intellectual/academic discourse today with fellow Nusantarans from Indonesia and Singapore apart from Malaysia.

The Fuqaha is in agreement as to the measurement of the dinar and dirham in misqal/mithqal.

The problem starts when the mithqal standards needs to be converted to grammes!

To the uninitiated, the metric system only came into being AFTER Prophet Muhammad SAW time.

HENCE, the question POSED is - " Why do we need to use present measurements if it leads to "bickering" amongst the proponents of dinar & dirham? "

ANYONE?