This is likely due to the scroll acceleration feature: by defaut in Sierra the scroll is accelerated and has some sort of "inertia" before it starts actually scrolling.
For the trackpad you might be able to "solve" the issue by deselecting Acceleration under Settings>Accessibility>Mouse & Trackpad>Trackpad Options... and trying to set scrolling to "without inertia", but I didn't test this solution since my problem is with the external mouse.
For a standard mouse this setting is as far as I know not configurable within Sierra, but it's configurable with third-party tools like USB Overdrive which is able to set the scroll behavior from "Accelerated" to "1 Line" and this restores the previous behavior. If your vendor offers a specific settings manager for your device it might work too.
Last edited: Sep 25, 2016