I asked an outfitter friend of mine this question and this is his reply.
A doe with a single fawn is usually a buck fawn.
A doe with twin fawns are usually at lest one buck fawn and a doe fawn, or , 2 buck fawns.
A doe with triplets is usually 2 buck fawn and a doe fawn, or can be vic versa
But these are not written in stone . You know mother nature ,anything goes.
He explained to me that bucks have a higher mortallity rate, fighting,he said you will never see a dumber deer than a button buck( curiosity killed the cat), and chasing does across the roads, mother doe will run them off and then they are on there own etc.........
I guess mother nature has figured this into the plan and the deer by nature then produce more bucks than does.