So, here is the
1850 infantry+artillery list I run.
So, there are a few things to do with infantry-heavy armies.
The first is blob squads. Take 3 infantry platoons with a commissar in each one as often as points allow. There are two ways to arm them: squatter (no power weapons or special weapons, just a couple of heavy weapons), which are a huge points sink for damage, but they're hard to clear off objectives. The other is power blobs (everyone has a power weapon, throw in a couple specials, and maybe a priest or some meltabombs), which are good for assaulting stuff and then holding what they took.
The second is mobility. It's rather low in guard infantry squads, but there are two solutions. One is to outflank with Al'Rahem with an astropath (dont' use Creed - he costs way more to let less stuff outflank), the other is to bring so many guys that just rush forward sprinting that you're always inevitably going to get SOMEONE there. Personally, I use the former, but I could see the latter possibly working with chenkov.
The third is firepower. You're going to be bringing a lot of PCSs, and you have access to take a whole lot of SWSs and HWSs. Make sure you use these to your advantage. For example, I have an infantry platoon with a power blob, al'rahem with 3 melta, a 3 melta
SWS and a 3 plasma
SWS. That is an AWFUL lot of hurt (especially since al'rahem gets "bring it down") for something that just popped out of nowhere.
Finally, note that not all infantry units are appropriate to an infantry army. For example, SWSs do what vets do, but for half the price (they're really only good in chimeras anyways), and penal legionnaires (who are good for minimizing the number of points you spend on troops).
Oh, and don't go for the gunline.