Running a large combined squad of 40 to 50 guardsmen (4 to 5 10 man Platoon Infantry Squads), all Sergeants armed with power weapons (Axes or maces, Axes preferred) and each 10 man squad having one flamer in it (Overwatch help, 4 or five x D3 automatic hits against a charging foe will generate a few wounds against them on the way in). Pair this with a basic (or Lord) Commissar and Priest attached to keep them from breaking, and hymns respectfully. A second group of Guard Conscripts, 30 to 40 strong, with a second priest and a regular Commissar attached as a flank tarpit unit.
Then add in a few (3 to 4) bare bones Veteran squads with the Forward Sentries doctrine to act as a Vanguard for your large infantry squads. Put them in cover, so their camo cloaks can help them stay alive, and let their snare mines help slow down charging foes from a flank.
Also, and I swear by this by the way, Krak grenades are your friend. It can add up points wise, but having a 40 to 50 man infantry squad charge in, the Zealot rule allowing for reroll failed to-hit, with Priest Hymns helping with re-roll failed saves they'll need to make before they swing, each guardsman attacking with one Krak grenade shot (
ST:6,
AP:4) is going to hurt something. You'll generally wind up inflicting at least 20 wounds on whatever you're fighting, assuming all models get to pitch in with their krak grenade attack, and then the Sergeants get to swing their 3 power axe swings at I:1. That's 12 to 15 attacks (Depending on # of Sergeants, 4 or 5 respectively) swings at +1 Strength (S:4),
AP:2. Odds are good you'll net another 3 to 5 wounds. If any enemy is left standing and doesn't fail leadership/is fearless then the next assault phase, wash/rinse/repeat. Even getting charged doesn't hurt too badly, as you'll still get on average 15 or so wounds with the 40+ Krak grenade attacks. This squad operating from behind an
ADL is also very fun as you can use the 4+ cover then jump the wall & charge them when they get close enough.
The thing is, Guard are going to get charged. That's just how it's going to work. The trick to it is building the unit to either make charging in supremely difficult (Veterans with Snare mines inside terrain) or built to charge them and/or absorb the charge and then rear back to slam the unwitting charging foe in the teeth with an avalanche of krak grenade attacks.
It won't work against every foe you face or every time you get charged, but it'll surprise your opponent enough to make them wary and hopefully slow the opponent down enough to let the rest of your force keep hammering away with big guns and vehicle support.
That's one solution for you that doesn't even require allies.
Not the be-all end-all, but it's fun none-the-less.
Take it easy
-Red__Thirst-