Pangolier + Templar Assassin

Why this works

Putting two high-tempo physical damage cores on one team looks like a way to overwhelm the enemy, but it creates fundamental problems. Templar Assassin needs a target held in place to unload her damage from Meld, and Pangolier doesn't offer that kind of lockdown. His Rolling Thunder is more about disruption and displacement; it can even knock enemies to safety, ruining TA’s setup with Psionic Traps. Both heroes also deal primarily physical damage, so a single player on the enemy team buying an armor item can blunt the impact of two of your main cores.

The game plan for this duo feels awkward from the mid-game onward. Both Pangolier and Templar Assassin need to farm aggressively to hit their timings, often competing for the same safe parts of the map. When fights happen, the lack of a big teamfight stun becomes obvious. The enemy can simply spread out against Rolling Thunder or use mobility to escape the slows. This forces the duo to rely on getting solo pickoffs to build a lead, which is a much less reliable path to victory than having a cohesive teamfight plan.