The last gun, assuming it’s the double barrel machine gun, is solid. Strong range, decent enough accuracy. You won’t be sniping with it, but it will punish anything you aim at. The big problem it runs into is it’s a ‘braced’ gun. What I mean by this is, you primarily want to secondary fire to stabilize it, then primary to fire. The issue here is that the ogryn is so large that they lose toughness incredibly fast to ranged fire. Which means your bracing is destroyed, which spoils your ability to reliably use this in all situations.
Though, the nice thing is, in every situation where you can’t use the ranged machine gun, you instead use the shield. Which is basically the only viable weapon on ogryn. No, seriously, they need to add the shield to every single weapon that’s not 2-handed simply because of how vital it is to Ogryn. And when you don’t need the shield, well, bring the dakka. Ammo economy is solid, damage is good enough. Getting forced out of using it is annoying but not the end of the world. Just bring a shield and you’re the perfect assist bro.