The theme thus far has been fighting in closed spaces. Let’s take a breather in the open field again.
ATGM are long-range high-AP missiles that make anything but the cheapest vehicles a stressful pain to use. It’s hard to provide fire support against a forest when the forest is shooting missiles that oneshot your 60pt tanks and twoshot the 100pt ones. Compared to vehicle-tab ATGM, infantry squads are exceptionally stealthy. This makes them hard to counter, because they break the basic push formula I described earlier, killing the fire support of a push without being spotted by the pushing infantry. Generally you need to either somehow sneak recon close enough to spot them, or smoke off the launcher.
ATGM infantry is always a good thing to bring if you can spare the deck space. Even if you don’t get any kills with it, the inconvenience you’re causing your opponent for just 30-40 points is always worth it. Don’t go overboard and spam it in large numbers – even a single squad is lethal enough. Be mindful that they run out of ammo quickly and require a fair bit of supply to rearm. ATGM infantry is mostly only useful on the defensive as it requires cover – either a forest or a town – and some distance between itself and the target.
Finally, a deckbuilding tip. There’s generally two to three types of ATGM infantry for each nation, each being a straight upgrade from the last. Don’t be cheap; always bring the high-end option. The cost increase is always worth it. A similar rule holds for MANPADS.