Any blower that is not positive displacement (like an air compressor piston) has what is called a fan curve (see below). This curve relates flow rate to pressure drop across the blower. If duct length pressure loss plus hood filter pressure loss plus make-up air pressure loss uses up much of the pressure capability of the blower, flow rate will drop quite a bit.

But there is hope because depending on relative characteristics, a supplemental blower in the duct path or externally wherever the duct exits will share some of the pressure drop, causing the flow rate to rise to where is hoped to be.

Now, the air flow has to be the same through both blowers, so their respective fan curves have to be consulted and blowers tuned, perhaps, to work well together. This solution is better applied when an inadequate installation already exists.

The easier approach is to buy a better blower (higher pressure loss capable blower) and use it instead as a single blower. Overall, the solution is situational and not amenable to glib advice.Example fan curve.

maybe post the floor plan to get the kitchen to an outside wall.