It has been a while since I used fleets but there were certain things I did:
1/ Use tight formation so they stick close
2/ Use standard arming so they don't use overloads
3/ Switch to each ship in turn and change settings I don't like (mostly eliminate WW and change the power priorities to mine)
4/ Fire on command
5/ In line flight formation
I then as the ships closed in to attack would switch from controlling the 1st ship after it fired to controlling the 2nd, then to the 3rd and back to the 1st. It could be quite effective that way.
You can't get them to disengage separately though.