I'd cut off the numberpad of my laptop, center the touchpad and what's left of the keyboard. That would be my ergonomic setup.

That laptop served me well but it was a compromise between several factors. I think that at the time there were only an handful of 15" laptops without a numberpad and probably it's still like that. I eventually had to give up on that to get other features.

For my home laptop I ended up going for 13" specifically to avoid off centre / number pad layouts.

I'm sure there are plenty of better options if money is no object but it was mainly for light gaming, personal projects, video editing etc.

That's basically what I'm telling folks. My MBP16 is fantastic in that regard. I use the integrated touchpad only