Nothing will burn or go bang if you try
The MoBo will accept or reject-
So try it and see.
Leave an existing one in slot 0
that will be the 'master' and then slot the others in one at a time first into slot one if OK slot another into slot 2
Sandra will tell what is going on - or not- in addition to the bleeps of protest from the MoBo if it does not like one or tother.