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