Was there ever any official word on whether or not EU3 will support dual processors? If that is not enabled in this game then most likely any type of Pentium 4 should run the game just fine because if the developer didn't feel liking coding it to run on two cores, it probably does not need that much processing power.
Also, just a little info on Intel processors.
The Core 2 Duo is a slightly optimized Core Duo Processor with x64 bit enabled as well as x32 bit. Intel made claims that the Core 2 Duo runs %30 faster on average, than a comparable Core Duo. These claims are not true and it is only marginally faster. However I am sure EU3 does not utilize 64 bit code so anyone with just Core Duo should only be worried about what kind of video card they have.
Pentium 4's and the Pentium D's are widely disliked because they generate a lot of heat and use a lot of watts to power them. This means they are bad candidates for over clocking and generally an inefficient architecture. They are not as bad for gaming as a lot of people make them out to be.
The only Intel people that should be worried are those with Celeron processors. I hope I don't eat my own words in the near future!