A large part of Malcolm's sound is his guitar. It starts there.
And Mesh, do what Beeps is saying. And really the most important part is just sitting with with your choice of sim and working with it.
Pick a setting and play five minutes with it. Tweak the distortion/gain about half of what you have it set to. Up or down doesn't matter. Play again for five minutes. Just start getting to know what the sound is like on that SIM. Then turn the treble up or down and play again for five minutes. See how that affects the distortion/ gain your getting. Do this for all the tone knobs.
Then try the same procedure on another model/amp whatever you want to call it. Try another SIM if you want. But just give yourself the time to become familiar with the sound each setting gives you.
Yes it is work. And it will take some time. But it is the best way to get to a sound your looking for.
Once your happy with the sound your looking for, you are 90% there. Play your part inspired!
Because the bottom line is you will have to tweak it to get it to set properly in the mix.
And the "journey" is the real purpose. Enjoy it!!