DAGs with an even number of members use the fail over cluster's Node and File Share Majority quorum mode and use the formula of (n/2)+1 to check how many members needs to be active for Database to mount. For Example if i have 4 node server and one witness server defined then as per formula I need (5/2)+1=3 nodes to be available for DB to mount.
Q1) what if I do not specify the File Share Witness in even number members DAG? and what would be the impact of not specifying the FSW and how DBs would be able to mount?
Q2) Does FSW also work as a voter or there is any other role of it?
Q3) What id I have 3 Node DAG? is it required to specify a FSW ? and if I define it , is it going to be of any use? if not, how the quorum will be decided?