if nobody else will answer you.. here is solution:
player 1 says: "ordering mortar"
chat says: reinforcements arrived
(now every player look at bottom minimap, or at the list of units.. it takes max 2 seconds) and if anyone else have mortar, send it to player 1.. if you get used to it, it takes max 5 secs.... it s not full solution but... I used to it when I play with my friends
