If you have a good router and sled set-up, then following up with a sharp smoothing plane should be fine. Basically you are substituting the router sled for the jointer plane. Goal there being to have an overall flat surface when you are done and then the smoother to get a finish ready surface.
I will disagree about good planes being expensive. Good new planes are expensive. Good vintage planes can be found relatively cheap. I've purchased excellent quality ones frequently for less than $20 and several for less than $10, they just needed a little clean-up and tune-up to get back to working order.
I will disagree about good planes being expensive. Good new planes are expensive. Good vintage planes can be found relatively cheap. I've purchased excellent quality ones frequently for less than $20 and several for less than $10, they just needed a little clean-up and tune-up to get back to working order.