Heya,
So im curious about the shape of the graph lines a what is prefered.
Some are more curvy, flat and some have a steep climb in torque at the start of the low RPMs.
In some cases when tuning gears I notice a drop in power before the gear change with the curvy powerbands where the powerband starts to drop.
Is their some kind of peak powerband shape for drag, racing, offroad etc?
I found a great example for you…
Usually when trying different builds, I want to see things like this, right? (E46 M3)
But just now, I saw this, with a 2013 Viper GTS
The new build has less peak power, but averages more hp in gear due to the plateau added by the cam upgrade. Hp is the only number that matters at a given moment on the road. The Porsche Taycan is equally fast pulling 100-200mph in a 2nd gear tuned for 200, or 240mph, because hp output is unchanged throughout the pull either way. Try it. 
Power is more than hps, and definetly more than just max hps. Tourque is also a essencial part of the picture.
Look at the engines useful powerband, that`s from the revs it is at when you pull in next gear, and to the point it
recs out. Lets say this is from 4k to 7k, a typical a 3k useful powerband. The sum of hp and tourque between these
rpm-points represent an engines useful power.
Some bigger engines might have a wider powerband with more tourque, these will need fewer gears than a smaller
high-revving "hps only" engine with a narrow powerband. this again is related to the cars weight, heavy cars needs tourque while lighter cars cant handle too much tourque. I`ll stop here, next chapter is about tires
Honestly it’s up to the individual what’s best. There are real arguments for ideal engines for particular types of events, but at the end of the day if you like an engine for a particular task, you’ll probably drive better with it than something someone else told you was ideal.
Learning tuning is a never-ending process. You’re not just learning about cars, physics, and mechanics, but also about yourself as a driver. There’s a bit of art with the science. Machine husbandry would not be an inaccurate term. The rest of us are just here as guideposts. We can start you on the path, give helpful advice along the way, and point out little foibles/oversights in the tuning, building, or PI systems.
But you’re already comparing hands on feel to the graphs. You don’t need any more guidance (at least on this subject). Any advice I give you at this point could be just as harmful as it could be helpful.
I guess the best advice I can give is have confidence in your new discovery. Experiment, build, test. Better for you to learn with your own hands and eyes than to be dictated to at this point. Oh, and make sure to have fun!