On the numbers this is not especially close. Both are 12 Nm, but the Alpha EVO 12 comes in $180 cheaper and scores higher on our rubric, carried by fidelity - its zero-cogging 5-pole servo and active cooling make it the smoother signal of the two, and reviewers rate it near the top of the mid tier for exactly that. The ClubSport DD 12 is a capable base, but at $699 it is asking flagship-adjacent money for a 12 Nm output that Simagic delivers more cheaply and, on our scoring, a touch better.
So why would you take the Fanatec? The answer is the ecosystem, and it is a real answer. Fanatec's quick-release rim catalogue is the deepest in the business, the QR2 is a properly good bit of hardware, and if you already own Fanatec wheels or you want the broadest choice of rims to hang off your base, the ClubSport DD keeps you inside that world. That lock-in cuts both ways - it is a reason to stay if you are already there, and a reason to think twice if you are starting fresh.
For a new buyer weighing them purely as 12 Nm bases, I would take the Alpha EVO 12: more money in your pocket, a smoother signal, and a higher score. The ClubSport DD 12 earns its place when the decision is really about the platform - Fanatec rims, Fanatec pedals, one connected system - rather than the base in isolation. Judge it on the base alone and Simagic wins; judge it on the ecosystem and Fanatec has the argument.