Z Fire

[Imp]

You probably won't have much mobility in a situation like that, if fact your units will be "pinned" even before their first casualties and will stay that way until the shooting's over, and the geography often makes flanking difficult, so the only option left is to bury your enemy under volley after volley of bullets.

Not the only option the better option is to use artillery, then your MGs to cover any holes, maybe if needs be the odd squad.
As arty & MGs cover multiple hexes you get more bang for your points & a higher chance of killing something to.
Use 50-81mm mortars as they have a high rate of fire if suppression is what your after.
Now your squads can actually take aimed shots & kill something