You don't need a numpad
You don't need a numpad on your keyboard. When was the last time you used it? Exactly, you don't even remember. All it does is create extra distance for your hand to the mouse.
Here's a gif of me, moving my hand, to my mouse
And here's the same gif, with... chocolate bar between the keyboard and the mouse. I didn't have a keyboard with numpad, but the width of the chocolate is close enough
When you do that movement hundreds of times a day, making it even a little bit easier can reduce strains. And if you really need a numpad you can just buy seperate one and place it on the left side.