Yes, absolutely. They are coming too early. They need to change it so that Call in units require some sort of teching as well. Tigers need T4 unlocked, etc.
+1
The problem isn't that the teching is too ineffective it's the Call-ins being too cheap and cost effective. The delayed teching is fine and improves the gameplay experience. There should be teching requirements for all Call-In Tanks. Somthing like Battlephase 3 for german heavys and either T3 or T4 building for Soviet Call-Ins. Maybe slightly adjust the prices to prevent T34/85 etc from becoming useless.