they're Central Nervous System depressants and combining them altogther can lead to possible overdose - which you obviously want to avoid.
if you;re unfamiliar with baclofen then my advice is take the drug by itself to familiarise yourself with its effects before you go combining it with other drugs. imo, and many others, baclofen is far from recreational but works great as a anti-spasmodic/muscle relaxant - it's purpose.
we can;t really give you any other advice as you haven't given us enough information to work with, ie - your benzo tolerance, how much alcohol you intend to drink - which should be no more than 1-2 standard drinkk and what the hell are mgd's? mogodon?
i'll send this over to basic drug discussion where these combo questions belong.
stay safe