I've read all this with great interest...
Ision: great analysis/assessment...
When I first was intro'd to Civ III 'twas the Vanilla version and I played the first few as the Romans. Then, since my roots are German, I tried the Germans, and I've played them exclusively ever since (I'd feel like a "traitor" if I didn't; but that's entirely subjective and slightly foolish I suppose)...
I haven't
always "won" with Germany, but I
have won more than I've lost, and, Ision you're quite right, it's quite satisfying. Once I get a handle on the level at which I'm playing (currently Regent), it gets a lot easier. Granted, playing the Germans can be challenging, at times, but that's my preference.
Love the Panzer's; especially when I can create armies (3x to begin with; 4x later) with 'em....
Once one gets past the MA, "combined arms" is absolutely necessary. Doesn't matter if we're talking naval or ground strategy; you have to have more than one slugger in your stable (personally I kind of like panzers (later, Modern Armor), mech inf, radar artillery, cruise missiles, and bombers (conventional and/or stealthy)). With Infantry backup for defense...
That's my two-bits worth...