No - what I'm talking about is you going to Coriolis/Inara, telling their new tool (which will for sure get built) what your desired outcome is, and then it shows you exactly how to set the sliders/web to achieve that. Additionally, there will be an Optimal Settings option, which will show you how to get up your entire ship. This is what sliders/webs become, and in very short order. There are people who think that they won't utilize a tool like that, but once they realize that the tool does indeed provide the optimal results, they will start using it as well. And they should, to be perfectly honest. There are some who enjoy handicapping themselves, but most people will go for the best result they can get.
You keep mentioning Gran Turismo - I don't know about that game, but I do know Forza Motorsport, and back when I was playing it a lot, I could go grab one of Davyskills' setups. It was eye-opening how much better the car performed when it was set up optimally, instead of using the standard, or what I thought might be "better." Your vision seems to be you tinkering with your ship (which I also like, by the way), but the reality is that either someone else is going to tell you how to tinker, or you will come to the same conclusion(s) on your own in a longer period of time. Either way, you end up in the same place (like the optimal setups for each track/car combination).
Once you are there, and have that knowledge, then you aren't really tinkering anymore, are you? That's one of the points that I'm trying to make, without saying it explicitly earlier. It just becomes another layer of standard upgrades, which is not what the Engineers should be. They are supposed to be able to work wonders, so to speak, but the only way those wonders can be achieved is with RNG.
Also - everyone who uses the Engineers does have the same chance on every roll, and they are equally accessible to every Horizons-enabled pilot who wants to put in X amount of effort into the system.
Riôt