The mistake that ancient FH2 devs did was to make the system too complex with too many variables. That's a totally normal mistake to do for people just starting out with amateur game design, everyone does it. (Just like new mappers spam the entire map with small planks, chairs, pots, pans etc)
Just looking at a complex game which is only about tanks, WORLD OF TANKS, our tanks are set up in pretty much the same way, with just as many different materials, small parts etc.... a tank in FH2 can easily have 10 different materials, same as in WoT
The difference is: they have a designed, real damage system for these tanks. We haven't. We cant shoot out parts of the tanks, we dont have the same scoping/sight mechanics, we dont have 3P camera making you more aware of the surrounding, we lack pretty much everything we need to make those materials useful.
It's done wrong to put it simply. The result is not "realism" it's annoyment. It's unpredictable behaviour with the tank, it's either getting 1s1k when you dont expect it, or unable to hurt enemy tank when you do expect it. It's getting no feedback if you even hurt him. It's aiming at a 50x30 pixel tank at distance and manage to hit him, but projectile hit some minor detail you cant even see, so now you sit there and "guess" if he received any damage. It's driving a tank that doesnt feel like a tank, it's being able to snipe infantry with the coax while at the same time being 1s1k by grass-ninjas. It's a system that fails a little on all points, pretty much the only thing that works as intended is the sights and the ammo-switch system. The rest is clunky, rough and un-engaging as it is. OK OK, it's not all bad, you still have fun and exciting rounds, dont you? I mean... the wtf moments dont take up more than say 30% of your overall tanking time, the rest is actually quite cool, isnt it? Otherwise you wouldnt be playing, or?
So we need to iron out all the annoying "wrong" things, make it more predictable/controlled/consistent, make an easier manageable system that allows us to easily go in and do these "fine tunes" that you say make FH2 so special. The problem right now is, we can't. We lack the "levers" to pull to put it simply, because our system is mega-complex and is using to many paramaters which alters the outcome of each shot. This what we will start to simplify, so that we can manage the system like we want - and as you like it as well. When Im saying simplify, you immediately jump to game-results (obviously since you only interact with the game while gaming, interestingly always refering to a completely other game from 2002) but Im talking about simplyfying the system so we can control it more easily. That is why things like materials, velocity, penetration (non existent term), damagedrop, deviation needs to be consistent and possible to overview easily.
I hope that cleared up some of this confusion, I think we sometime talk about different things here.