The modern anti-tank guided missile can hit a target several meters in diameter at ranges greater than five kilometers. While this level of precision is normally used to disable tanks, resourceful operators have often found the precise nature of ATGMs makes them useful for many other targets including infantry and even other ATGM teams. This has been especially notable during the Syrian Civil War, with the Free Syrian Army and Syrian Arab Army sometimes engaging in ATGM duels.
However, the High Explosive Anti-Tank (HEAT) warheads on most ATGMs are poorly suited to this kind of combat. While the heavy weight of some HEAT warheads may give them significant blast or fragmentation effect, the majority of explosive effect is focused on creating a hot jet of metal to penetrate armor.
Dedicated thermobaric or fragmentation warheads are more effective against infantry and structures as their explosive force is all projected outwards. They also can fit more explosives into the space given to them, as HEAT warheads have to have an empty conical or spherical portion that “focuses” the explosion into a jet. Fragmentation and thermobaric warheads fill that empty space with more explosives. The downside to these warheads is that they make the missile ineffective against heavy armor.