I'm just thinking that maybe people will think twice before nuking the enemy if your own allies' units are in the mix too, especially with howitzers which scatter so long.
Realistically it'll just make me hate my own team mates, even more.
edit: Though I doubt any change will come about since it'd drive most team game players would probably hate it.
That (removing FF or reducing it highly) would give more realistic aspect into the game. When artillery fires you don't make a charge with your infantry (reminds me old calliope barrages and waves of riflemen inside killing everything that rockets spared). If there is a barrage you just don't push. As someone above meansioned of course with expection ISG and mortar in autofire mode.
Attacking your own allies should be on the other hand reported and ban.