Skywrath Mage + Tinker

Why this works

Competing for the same resources slows down the entire team. Both Tinker and Skywrath Mage are incredibly greedy heroes who need a lot of gold and solo experience to hit their critical item timings. When they share a map, they are constantly taking farm from one another, meaning neither hero gets online as quickly as they should. Their damage is also almost entirely magical. This makes it very straightforward for the enemy team to build items that counter both of them at once, like a Pipe of Insight, severely reducing their impact.

This draft leaves the team vulnerable for a long stretch of the game. While Tinker is trying to secure his Boots of Travel, the team often lacks the power to defend towers or contest objectives. Skywrath can provide some burst, but without a strong initiator or frontline, he is easily focused down. Opponents exploit this by forcing fights and pushing early, knowing that the duo can't effectively respond together. The team is forced to play passively and hope to survive until their cores are farmed, which often comes too late.