geln0r, I've long ago made a (private) spreadsheet for this and pointed out that the "ideal ratio" is very fluctuant and without factors such as BE Sci, Population Mods, %Land to allocate, Def Spec Value... people cannot give appropriate values. I've even pointed out that Homes CAN be more effective than TG's / Forts, but people have all sorts of reasons for not liking that.
And you're not even factoring Offense / NW yet.
In short; people seem to prefer not to actually think about the game and just play it.
On another note: While mixing TG's and Forts is "okay", do realize that you'll have unbuilt acres for most of the war (Including buildings in progress) and that if you're DEPENDING on Forts for your defense, that you'll rapidly lose your DME while growing. On the other hand, you could just phase out the Forts and go pure TG's while in war (: