Don't wargames also have a strong simulationist element, in contrast with more abstract games such as chess? Indeed, I thought wargames usually emphasised sim above all, with game coming in second place.
I'm hardly an expert on either wargames or Forge terminology, but here's what I'd say...
Wargames have simulationist overtones, and simulationism advises the 'balance' choices made among the pieces, but wargames are never actually played for simulationism. You never play a battle which is blatantly one-sided, you never play "survivalist horror" (which is what a one-sided battle resembles). You never worry about supply lines, or diseases among the troops, or latrines, or foraging, or what happens when your sniper miniature gets a "Dear John" letter the night before.
What you play are
battles in which the winner is very much in question, such that the skill of the players ought to be the element which determines the outcome. You play battles which are contested
challenges, with clear-cut victory conditions.
So, it would seem to me that simulationism might inform the trappings of wargames, but never the practice.
Cheers, -- N
PS: IMHO the difference between wargames and a game like chess is that the former is balanced but asymmetric in terms of specific unit capabilities, the latter is symmetric in specific unit capabilities. This is also the difference between Starcraft (asymmetric) and Warcraft II (symmetric).