Going back when you've played a few hundred hours with the expansions is too hard for me, it just isn't fun.
Obviously it up to duffyman if he want to restrict it to vanilla in order to let in more people.
Also my heart skipped a beat when I read the headline.
Might be a sign that I'm abit of a Paradoxian when it takes effort to read EU4 as anything other then Europa Universalis IV
PS. Warfare in ArmA2 was awesome, I'll give this a try for sure.
Excuse my ignorance if you please, but is Warfare Benny Edition with or without AI and Basebuilding?
EDIT; OP might have been edited while I was posting... or I had an aneurysm while reading the post first time, both plausible.