I agree with your take, but none of these games are as frustrating as Bayou Billy. I wonder if some dev at Konami just hated Americans?

The NES version is harder than the Famicom version; enemies in the beat-'em-up stages are more aggressive and have more health, the player starts the shooting stages with less ammunition, and the driving stages have narrower roads. The driving stages in the Famicom version also give Billy's jeep a health gauge, allowing it to withstand collision from enemy vehicles and road hazards, a benefit not available in the NES version.

This art actually looks like it's based on an Apple Extended Keyboard II. It's been a really long time, but if I remember correctly, those had ADB ports for the mouse on both the right and left side of the keyboard (you could use either, or possible both for other ADB devices).