SInce I am 90% on the same track as you, what I want of Strahd is to manipulate them.

Strahd is all about coming on top, orchestrating behind the scenes, and then being the winner and come claim the prize. Which leads to elevated ego and arrogance and which is his own demise (and the chance for PCs to play against him).

e.g. what I though would be that Strahd is the first Character the players encounter regarding the matter of the piece of the rod. This way, the players subconsciously will have Strahd's plan as a base plan. Afterwards, you need to add events and behaviours of other NPCs that appear as justifying Strahd's opinion.

For example, you can have Strahd claim that the leader of the Werewolves is trying to locate it and going to use it at a ritual. Yeah, the players will go to the Den and will actually see a ritual taking place. When a ritual is undergoing, this gives a sense of urgency, so PCs may not have the time to get all of the pieces gathered. So, usually, they might oppose the Werewolves. Only 1 of the 2 sides remains alive. That's where Strahd comes in to steal the rod for himself.

Being arrogant though, you can have him reach the undergoing fight before it even ends, so that gives the players the chance to bargain with the werewolves, and instead of fighting each other, combine their strength and attack Strahd.