Let’s recap the main points of the infantry section.
In open space pushes, the job of infantry is to lead, forcing enemies to either shoot it and expose themselves or concede the forest/town. The killing is done by fire support in the form of ground transports, tanks, or rocket helos.
In enclosed spaces, infantry does most of the work. In forests infantry engages first, shortly followed by transports or tanks which aim to inflict maximum damage before being targeted by RPG. As vehicles still participate it is important to use well-rounded infantry in forests. Towns on the other hand are too hard for vehicles to effectively operate in, so just one or two squads with decent AT can cover a large number of killer infantry without any anti-vehicle capability.
When taking a forest, an attacker has to win twice – first by achieving open space dominance and securing entry, then by winning the infantry fight for the deep forest. A defender only needs to prevent one of these from happening, so for example conceding the entry point but stockpiling infantry to make the inner forest impregnable is an option for large enough forests.
Many transports are cheap and just brought as a battle taxi with minor forest support capabilities, but the heavier options shouldn’t be overlooked. An autocannon IFV makes for a very versatile unit when working together with the infantry it carries, while a grenade launcher vehicle can contribute to forest fighting as much as an actual infantry squad.