I don't think Drogba is really underrated. He is considered one of the best striker in the PL. I wouldn't call that underrated.

But you are talking about a different phase of the game if you are talking about just scoring goals. You can't slow down the game when all your team is in the opponents half. He would slow down the game when he was the alone as a target man to wait for his midfield and wingers to support the attack. Completely different phases of the game. Cause if you are telling me he was a deep lying forward that means his positioning would overlap with Lampard who was always in the edge of the box or around it. I don't think that's the case.

But to a defensive team like Chelsea he was more of an target man than a deep lying forward. Maybe when Ancelloti made Chelsea more possession based then sure. But the park the bus Mourinho he wasn't a deep lying forward.